The polling is (should be) done, and the vote takes place tonight at the Iowa caucuses. 

Republicans: Donald Trump has led in all recent polls, averaging a four point margin over Ted Cruz in the last five polls. Rubio has been gaining some momentum in recent surveys, although the 'gold star' Iowa poll out over the weekend had him well back of Cruz and Trump. It wouldn't be terribly surprising if there was a very close 3-way battle tonight; perhaps with Trump, Cruz and Rubio finishing within 5% of each other.

Democrats: Polls have varied widely in this race, although many of the most recent ones have shown a slight lead for Hillary Clinton. It appears that turnout for the Sanders campaign will be crucial in determining whether the Vermont Senator can score an important early win. Either way, it is looking good for Sanders in next week's New Hampshire primary. A new poll out this AM has him up by 31 points over Clinton.

Third term Republican Reid Ribble (WI-08) announced his retirement over the weekend, turning a safe Republican district into a toss-up race for 2016.

37 House members have announced they are not running this year, 22 Republicans and 15 Democrats. Of those, eight Republican seats are highly competitive (toss-up or lean per Sabato's Crystal Ball). Four are competitive on the Democratic side.

Seven members of each party are leaving to run for the U.S. Senate; a single Democrat is running for governor with another running for local office. The remaining six Democrats and 15 Republicans are retiring (or have not announced plans to run for another public office).

The full list of departures, as of February 1, follows:

The final pre-caucus Iowa poll released tonight showed Donald Trump with a 28% to 23% lead over Ted Cruz, with Marco Rubio at 15%. This is a 6 point improvement for Trump over the prior poll in mid-January, turning a 3 point deficit into the 5 point lead.

On the Democratic side, Hillary Clinton leads Bernie Sanders by 45% to 42%. Both Clinton and Sanders made small gains over the last poll, with the net margin not changing much.

The poll is conducted by Selzer & Company, the best pollster in politics, and sponsored by the Des Moines Register.

The New York Times has endorsed former Secretary of State Hillary Clinton for the Democratic nomination while giving the nod to Ohio Governor John Kasich for the Republican nomination.

The Times says that, in Clinton, the Democrats "have the chance to nominate one of the most broadly and deeply qualified presidential candidates in modern history." While complimentary of Vermont Senator Bernie Sanders, the Times says that he "does not have the breadth of experience or policy ideas that Mrs. Clinton offers."

As might be expected, the paper was not as glowing about the Republican field, finding businessman Donald Trump and Texas Senator Ted Cruz "equally objectionable for different reasons." In a lesser-of-evils pick, the times gives the nod to Kasich: "...though a distinct underdog, is the only plausible choice for Republicans tired of the extremism and inexperience on display in this race."

Iowa Poll

The pre-caucus Des Moines Register Poll, conducted by the well-respected pollster Selzer & Company, will be released this evening at 6:45PM ET. This should be our final look at how Iowa is shaping up before the actual caucuses take place. Their last poll showed Ted Cruz with a three point lead over Donald Trump, down from ten points before Christmas.

More recent Iowa polls have shown Trump ahead, averaging a 6 point average lead over Cruz. Marco Rubio has been showing signs of strength as well, possibly helped by the Register's recent endorsement of him.

Donald Trump has leads ranging from 7 to 19 points over Ted Cruz in three early voting states, a new set of polls from NBC News / Wall Street Journal / Marist shows. On the Democratic side, Bernie Sanders and Hillary Clinton have huge leads in New Hampshire and South Carolina, respectively, while Iowa is essentially tied four days in advance of the February 1 caucuses.

Trump leads by 7 in Iowa, the poll found. This is consistent with most recent polls, as is his much larger 19 point lead in New Hampshire. There's been less polling in South Carolina, although here too there's not much new with Trump's 16 point lead.

Marco Rubio has made nice gains in Iowa; this latest poll has him at 18%, his highest number there yet. The top 3 candidates in Iowa now have support from 75% of likely caucus goers. In New Hampshire, it continues to lok like a tight battle for 2nd, with Cruz, Rubio and John Kasich basically tied, with Bush and Christie within the margin of error. 

For the Democrats, the real battle seems to be for Iowa. Sanders has pulled well ahead of Clinton in New Hampshire, while Clinton continues to dominate the polling in South Carolina.

 It will be interesting to see how the polls from New Hampshire and South Carolina change after Iowa has had its say.

Donald Trump and Ted Cruz remain locked in a tight battle six days before the February 1 Iowa caucuses, a new Quinnipiac University poll found. These results are virtually unchanged from Quinnipiac's prior poll released two weeks ago. 

Overall, Trump holds about a five point leader in the 270toWin Iowa average, with much higher volatility across pollsters, ranging from a two point lead for Cruz to an eleven point lead for Trump. Rubio has been consistent in the low teens, and looks likely to finish third.

Weather

Part of the reason the Iowa polls are so varied is that the caucus format is difficult for pollsters to model; much depends on which organization does the best job at getting its supporters to the caucus sessions.  One area that impacts turnout is the weather. At this point, the National Weather Service is showing pretty benign weather for next Monday. Des Moines shows mostly cloudy, with a high of 34, while the Cedar Rapids forecast is for a slight chance of snow with a high of 33. These highs are close to the average for early February.

Another billionaire might want to shake up the 2016 race. The New York Times reports that former New York City mayor Michael Bloomberg is looking at a potential 2016 run as an independent. Bloomberg has flirted with the idea in the past, but has always concluded he couldn't win. He sees a potential opening in a 2016 race that could see a scandal-weakened Hillary Clinton or a far-left idealogue against a far-right idealogue or a political novice with high unfavorable ratings.

If you'd like to play around with this idea, we've got a version of our electoral map that allows for third party or independents to be included.

How could Bloomberg win? Let's say he's able to win a few states and that nobody in the race reaches 270 electoral votes. In that case, the U.S. House would pick the president, with one vote per state. Republicans control the majority of state delegations so a Sanders or Clinton choice would be doubtful. Perhaps a centrist independent would be more appealing than Trump to at least some Republican states who might then join up with some Democratic delegations to give the presidency to Bloomberg. An absolute majority of the states (26) must agree on the winner.

Lots of Iowa polling out today, eleven days before the February 1 caucuses. Not a lot has changed on the Republican side, while both Clinton and Sanders can point to positive results, although it remains unclear who is actually leading there.

Republicans: Four polls today. Two of them showed Trump and Cruz basically tied. Trump leads by about 10 points over Cruz in the other two. It is worth noting that the two polls with Trump well ahead have a much smaller sample size. Trump and Cruz remain the clear frontrunners with Rubio the only other candidate averaging in double digits. 

Iowa has 30 Republican delegates, to be allocated proportionately. This is about 1.2% of total Republican delegates. 1,237 delegates are needed for the nomination. All primaries and caucuses prior to March 15, except South Carolina, will allocate proportionately. 

Democrats:  Three polls today, two of which show Clinton ahead by 9 points while a CNN/ORC poll has Sanders with an 8 point lead. While CNN/ORC perhaps the most well-known of today's pollsters, it is again worth calling out the small sample size for that poll (as well as the Emerson College one). Appears to be anyone's guess who is actually ahead at this point.

Iowa has 52 Democratic delegates, to be allocated proportionately (some statewide, some by Congressional District). This is about 1.1% of total Democratic delegates. 2,383 delegates are needed for the nomination. 

Ohio governor John Kasich has moved past Marco Rubio and Ted Cruz into 2nd place in New Hampshire, based on an average of recent polls. Kasich had 20% in a poll out today from American Research Group, up 6 points from their prior poll just a week ago.

Donald Trump holds a commanding lead, on average, but only up by 7 points in this latest poll. The New Hampshire primary is in 3 weeks, on February 9th.

While Kasich is gaining traction in New Hampshire, he's not seeing that translate in Iowa, where he's barely registering at 3% or nationally, where he's at about 2%.

On the Democratic side, Bernie Sanders had a 6 point lead over Hillary Clinton, consistent with the average of recent polls.

As the three remaining Democratic candidates make final preparations for tonight's debate in Charleston, SC (9 PM ET on NBC), a new poll from that network, in conjunction with The Wall Street Journal shows Hillary Clinton with a commanding national lead over her closest challenger, Vermont Senator Bernie Sanders.

While recent polls indicate a very competitive start to the election calendar, the states after that are currently looking much more favorable for Clinton. This is borne out by the 25 point lead she has over Sanders in today's poll. In fact, Clinton's lead has grown 6% from the last NBC/WSJ poll:

As noted, the early states of Iowa and New Hampshire are much closer, with Sanders leading in most recent New Hampshire polling. The challenge for the Sanders campaign will be to close strongly and outperform expectations in those two early states, hoping that the added visibility this will bring will begin to move the needle in his direction. As of now --where polling is available -- Clinton has a large lead in Nevada and South Carolina, as well as the many states that will vote on Super Tuesday March 1st.