UPDATE: The U.S. Supreme Court has denied the Republican appeal to block implementation of the new map.  This would seem to close the door on this issue -- the new district boundaries ordered by the Pennsylvania Supreme Court will be effective for the 2018 midterms.

===

A panel of federal judges dismissed a challenge to the redrawn Pennsylvania congressional map. The ruling comes one day before the March 20th deadline for candidates for the U.S. House to qualify for the state's May 15 primary. A separate appeal to the United States Supreme Court remains outstanding. This is the only remaining court that could halt the redistricting.

Although Republican Rick Saccone has yet to concede last week's 18th district special election to Democrat Conor Lamb, he is gathering the signatures needed to file in the new 14th district. This new district includes much of the prior 18th, but is even more GOP-friendly. Donald Trump won the old 18th by about 20 points, while those in the redrawn 14th voted for him by 29 points.

Lamb is expected to run in the new 17th district, which includes about 55% of the former 12th district, currently held by Republican Keith Rothfus. The district now includes more of Allegheny County and is thus expected to be quite competitive this November. Assuming Lamb is eventually seated, and if both make it through the primary, this will likely be the only district where two incumbents will face off in the general election. (Five of the state's incumbents have already announced they are not running for re-election).

The map below shows the current ratings for each of the new districts for November's election. The 14th is safely Republican, while the 17th is considered a toss-up. There are three other toss-up races near Philadelphia. Most of the remaining districts are safe Democrat or Republican, although there's a possibility the 8th and/or 10th district could become competitive. Ratings courtesy of Sabato's Crystal Ball.

Democrat Conor Lamb is the apparent winner of the special election in Pennsylvania's 18th congressional district, according to a projection from NBC News. Out of over 228,000 votes counted, Lamb leads by just 641 votes over Republican Rick Saccone. All that remains to be counted are some absentee ballots. While this could change the margin slightly, it is not believed that there are enough of these to make a difference.

Lamb declared victory early Wednesday. Saccone has not yet conceded. The Associated Press has not yet made a call on the race due to the possibility of a recount.

Although the party has come close in some deep red districts, a Lamb victory will make him the first Democrat to flip a Republican House seat in a special election during the Trump era. Republicans will have 238 seats, Democrats 194, with 3 vacancies. (Democrats did gain a Senate seat in the recent Alabama special election.)

The next special election is scheduled for April 24th in Arizona's 8th congressional district. The seat was vacated by Republican Trent Franks late last year.  That race features Republican Arizona State Senator Debbie Lesko against Democrat Hiral Tipirneni, a physician. If anything, this suburban Phoenix district is a bit redder than the one contested in Pennsylvania Tuesday -- Donald Trump won here by 21% in 2016. No polling of the general election is available yet; Republicans are favored to hold the seat based on a review of forecasts by various pundits.

It's a nail-biter in Pennsylvania's 18th district tonight. With 99% of the vote reporting, Democrat Conor Lamb leads by about 0.4% over Republican Rick Saccone.

It looks like what is left is a couple precincts in Westmoreland County and some absentee ballots, most of which will apparently be counted tonight. 

The AP has indicated that it is not prepared to make a call tonight due to the possibility of a recount.

ADVISORY: The Associated Press is not declaring a winner in Tuesday's special election for PA's 18th CD because the race between Democrat Conor Lamb and Republican Rick Saccone is too close to call.
Under PA state law, supporters of the trailing candidate can request a recount.

— Stephen Ohlemacher (@stephenatap) March 14, 2018

The special election for Pennsylvania's 18th district is today. The winner, Republican Rick Saccone or Democrat Conor Lamb, will complete the term of Republican Tim Murphy who resigned last fall. This article, from FiveThirtyEight, does a very nice job of previewing the election, along with what to watch for as the results come in tonight. Polls are open until 8PM ET.

Recent polling has Lamb slightly ahead in what has been a solid Republican district in recent years. President Trump won the district by about 20 points in 2016 and Murphy's re-election that year was uncontested. Democrats have consistently outperformed the presidential results in the congressional special elections held during the Trump presidency. However, Republicans have held all five* seats in the House. Democrats did pick up a Senate seat in Alabama.

Seen as another referendum on the Trump presidency, both parties are throwing a lot of money at the special election. While that's good for Pittsburgh-area media companies, this district will not exist in its current form next year. As part of a court-ordered redistricting, a large portion of the current 18th will be in the redrawn, safely Republican, PA-14 this November. As a result, if the Democrat Lamb wins today, he's most likely to run in the new PA-17 against 'incumbent' Republican Keith Rothfus. Even if the Republican Saccone loses, he could keep the campaign together to try again in the hospitable PA-14 this fall.

The Pennsylvania 18th District is one of four current vacancies in the U.S. House. The other three:

• AZ-08 This seat was held by Republican Trent Franks | (Special election is) April 24th
• OH-12 This seat was held by Republican Pat Tiberi | August 7th
• MI-13 This seat was held by Democrat John Conyers, Jr. | November 6th

* California uses a top two primary to determine the general election match-up. The 34th District special election was contested between two Democrats.

The Mississippi Senate special election has been added to the Senate Interactive Map. The winner of that seat will complete the final two years of Sen. Thad Cochran's term. Cochran announced he will resign as of April 1st. Mississippi's Gov. Phil Bryant will appoint a temporary successor who will need to participate in November's election should they wish to continue to serve. 

There are now 35 Senate elections that will take place on November 6th. Democrats hold 26 of these seats, Republicans 9. To win control, Democrats must gain two seats. As we've noted many times, it is an uphill climb. The most likely path is to hold all 26 seats, and flip Arizona and Nevada. Falling even one short of that would require a major upset in a deep-red state such as Texas or Tennessee.

While the 2018 environment favors Democrats, running the table in 26 party-held seats means winning in ten states where Donald Trump won in 2016, including five where he won by 18% or more. These include West Virginia (Trump by 42%), North Dakota (36%), Montana (20%), Indiana (19%), and Missouri (19%). An Axios/Survey Monkey series of polls this week showed Trump's approval remains above 50% in all those states with the incumbent Democrat trailing. The Senate heats were mostly against a 'generic' Republican at this point, so we wouldn't get too caught up on any single result. The larger point is that Democrats cannot afford even a single misstep in some very difficult states for them.

Here's how each race is currently rated by Sabato's Crystal Ball, Inside Elections, and The Cook Political Report. The table on the left lists any race where one or more of the pundits thinks it is or could be competitive. Conversely, the bottom right lists the 17 races that are safe for the incumbent party. The table at top right summarizes everything. There are currently 14 races with one or more leaning/toss-up rating. This number should decline as the individual match-ups become known.

The team at Sabato's Crystal Ball has made a number of rating changes for the November House races; all of which move in the direction of the Democratic party. The cumulative effect is that, for the first time this cycle, Republicans are favored (leaning Republican or better) in fewer than 218 seats. 218 is the magic number for control of the 435-member House, when there are no vacancies.

With the changes, Republicans are favored in 214 seats this November, Democrats 197, with 24 toss-ups*. Looking at the most 50 most competitive races (toss-ups + leans), Republicans currently hold 45 of them. None of the Democratic incumbents in the five remaining seats are running this November. Put another way, every Democrat seeking re-election this fall is considered safe or likely to hold the seat.

At this point, control of the House is clearly in play, and the number of competitive seats is expanding. However, we're still eight months out from the election, so much can change. If the trend stabilizes, and Republicans can hold the seats where they're currently favored, they don't need to win all that many of the toss-up districts to keep the House. Conversely, if the environment for the GOP continues to worsen, Democrats could easily surpass the 218 they need to take the gavel from Paul Ryan.

Click or tap the map above to explore the interactive House map and create your own forecast. The map has recently been updated to make it easier to use.

* Sabato has also moved their rating for next Tuesday's Pennsylvania PA-18 special election to toss-up. As part of the court-ordered redistricting, a large portion of the current 18th will be in the redrawn, safely Republican PA-14 this November. If the Democrat Conor Lamb wins Tuesday, he's most likely to run in the new PA-17 against 'incumbent' Republican Keith Rothfus. In any case, our map is looking beyond the special election to the ratings for November, which gets us to the 214 Republican total, with 24 toss-ups. 

Seven-term Sen. Thad Cochran, Chairman of the Senate Appropriations Committee, announced he will resign his seat on April 1st. Cochran, 80, cited health problems in announcing the decision, according to The Associated Press. The Mississippi Republican is currently the 3rd most senior member of the Senate, behind only Democrat Patrick Leahy of Vermont and Republican Orrin Hatch of Utah. Hatch has previously announced he will retire at the end of 2018.

The Republican Gov. Phil Bryant will appoint a temporary replacement. A special election will be held on November 6th, coincident with the 2018 midterms. The winner of that race will serve the remainder of Cochran's term, which will next be contested in 2020.

Mississippi joins Minnesota with both Senate seats up for election in 2018. Republican Roger Wicker is running for a 3rd term in the regularly scheduled election. That seat is safely Republican. Sabato's Crystal Ball is starting the special election race as 'Likely Republican', although it is worth noting that no state in this 'double-barrel' situation has elected Senators of different parties since 1966. 

That the rating is 'likely' instead of 'safe' could partially be due to one quirk of Mississippi special election law. There will be no party primaries and the November 6th election will be nonpartisan. All candidates will run on a single ballot, with party affiliations not listed. If no candidate exceeds 50%, the top two will meet in a runoff. If that involved a Democrat vs. a controversial Republican, there's at least a small chance of a repeat of an upset like we saw in neighboring Alabama late last year.

There will now be 35 Senate seats contested in 2018; 26 are held by Democrats and 9 by Republicans. We'll be updating the Interactive Senate Map in the days ahead to reflect this new race.

We've updated the 2018 House Interactive Map to reflect the redrawn boundaries for Pennsylvania's 18 congressional districts. Unless blocked by the Supreme Court, these borders are expected to be in place for both the 2018 and 2020 elections. For more information on how we're handling the changes on the map, see 2018 Pennsylvania Redistricting.

The revised map is somewhat more favorable to Democrats, particularly given the overall political environment. That party is also benefiting from departures, as four of 12 Republican incumbents are not seeking re-election. An analysis by Sabato's Crystal Ball goes into detail. At a high level however, there are now five safe Democratic seats and one likely Democratic. In addition there are now three toss-up districts in the Philadelphia area. Contrast that to the five seats Democrats hold today and a gain of anywhere from one to four seats seems plausible.

Note that the March 13th special election in the vacant 18th district will take place within the old boundaries. That race, in a district Donald Trump won by 20 points in 2016, was moved to toss-up this week by The Cook Political Report. The old 18th is now largely the new 14th district, which is even more Republican-leaning. The Sabato article discusses the implications for this race on November. The main takeaway is that if the Democrat Conor Lamb wins, his best bet to stay in Congress is to run in the 17th district against Republican Keith Rothfus.

The new Pennsylvania borders could also prove to be critical in who controls the House after the midterms. Looking at the entire country, Republicans currently control 238 seats, 20 more than the 218 required when there are no vacancies. (There are currently four opens seats, including the aforementioned one in Pennsylvania). The latest projection for November has Republicans at least slightly favored in exactly 218 seats, the lowest it has been this entire cycle.  

Lawsuits challenging the winner-take-all system of allocating electoral votes were filed in four states Tuesday. The filings took place in four states which have voted for the same party in the last 7 or more presidential elections. These include California and Massachusetts on the Democratic side and the heavily Republican states of Texas and South Carolina.

The suits do not challenge the use of the Electoral College system - which is enshrined in the U.S. Constitution - but instead that winner-take-all disenfranchises many voters. The ultimate goal of the plaintiffs is to establish an allocation of electoral votes proportional to the popular vote across the 48 states that today use winner-take-all. Nebraska and Maine use a different method that partially allocates electoral votes by congressional district.

The plaintiffs vary by state, but include the League of United Latin American Citizens and former Massachusetts Gov. William Weld. The legal team is led by David Boies, who represented then Vice-President Al Gore in the Bush v. Gore case that resolved the disputed 2000 presidential election. In that election, as in 2016, the Democratic nominee lost the election - by falling short of 270 electoral votes - despite winning the popular vote.

This isn't the first effort to modify winner-take-all. Several state legislatures have introduced their own proposals over the years. These are almost always partisan efforts, occuring when the party controlling the legislature is not the one winning in presidential races. In our Gaming the Electoral College feature, we look at the impact of various methodologies that have been proposed.

As expected, the Pennsylvania Supreme Court has come out with a revised map for the state's 18 congressional districts. 

Here's the current map (with incumbent party)

The 'instant punditry' on Twitter is that the new map is quite favorable for the Democrats, although we haven't seen any specific district-by-district analysis as of yet. Republicans will almost certainly challenge the ruling.

The full ruling, along with dissenting opinions can be found here.