Hillary Clinton won our closely-divided straw poll, with 52.2% saying she won the debate vs. 47.8% for Donald Trump. 9,201 votes were cast (after duplicate submissons were removed) in this non-scientific survey.

When we reported preliminary results Tuesday morning, Trump was leading 50.8% to 49.2%. As we dug into the numbers, we found Trump did much better among those that voted just after the debate, while Clinton got stronger as the hours went along. About 50% of votes were cast between the debate's end and 1AM ET, with Trump winning by about 52-48%. Thereafter, Clinton won by 56-44%. That 8 point swing gave Clinton the four point overall margin.

Since we didn't ask other questions, it is hard to know the reason for this shift. However, we don't recall ever seeing anything close to this kind of a time-based change of opinion in our prior straw polls. For whatever reason, first impressions did not last after Monday's debate.

This is a close election, with a divided electorate, and last night's performance only served to reinforce already made-up minds. That's one way to interpret our closely divided straw poll, which found no clear winner of the first presidential debate.

With over 6,000 votes cast (after removing duplicates), Donald Trump has received 50.8% of the vote, while Hillary Clinton is at 49.2%.

The voting is still open. We'll update the results later today.

Who won the first presidential debate? Vote in our straw poll. We'll publish results on Tuesday.

Heading into tonight's first presidential debate, signs point to a presidential election that could go either way. Hillary Clinton has an average lead of about 3 points over Donald Trump in the national polls. However, the four most recent polls, out yesterday and today give her a lead of only about 1.5 points.

At the state level, recent polling also points to a tight race. The map below highlights all states* with a current polling spread of five points or less. 11 states, representing 156 electoral votes. Keep in mind that only four states were decided by five points or less in 2012. 

The forecast models from FiveThirtyEight, from which we've derived electoral maps (updated hourly), have also tightened considerably in recent days. 

The presidential election is in 43 days. Some early voting is already underway.

* For this map, we've excluded Texas and Mississippi due to limited polling, all of which was prior to the recent Trump surge. We do continue to show those as toss-up, along with additional categorizations (leaning, likely) in the electoral map based on polls.

FiveThirtyEight is forecasting the presidential election with three models.  In each of these approaches, state-level winning probabilities are assigned to the candidates with each update of the forecast.

We've created an electoral map for each model that will update with changes in the FiveThirtyEight state-level probabilities. For example, the 'Polls-only' model as of Sunday morning translated into the map below.

See the article Electoral Maps Derived From FiveThirtyEight Forecasts for the most current maps, along with links to interactive versions.

The map below shows states with polls released today. Coloring reflects the survey results. Within five points is shown as toss-up, while a spread of greater than 10 points yields the darkest blue/red. The lighter blue/red is for spreads of 6-10 points.

Against other recent polls, today's polls were better for Clinton in Wisconsin and Virginia, while Trump can be pleased with survey results in Iowa and Georgia.

The full list of recent presidential polls can be found here, with the full set of polling averages also available. Clinton leads by 237-120 in the electoral map based on polls.

The map below summarizes the states where polls have been released since Sunday. Coloring reflects the survey results. Within five points is shown as toss-up, while a spread of greater than 10 points yields the darkest blue/red. The lighter blue/red is for spreads of 6-10 points.

The full list of recent presidential polls can be found here, with the full set of polling averages also available.

In this recent batch of polls, Trump is doing better than might be expected in several blue states, including Wisconsin (Clinton +2), Maine (Clinton +5, but Trump +5 in 2nd District) and Minnesota (Clinton +6). Clinton is performing better in Florida (Clinton +5) and New Hampshire (Clinton +9) than in other recent polling.

It takes 270 electoral votes to win the presidency. What if nobody reaches that threshhold?

There are two main scenarios where this could occur. Neither is likely at this time, but fun to think about. The first is a 269-269 tie between Hillary Clinton and Donald Trump. The 2nd involves one (or more) third party candidates getting enough electoral votes so that neither Clinton or Trump reach 270.

There are 97 possible ties based on the states that currently look most likely to be competitive in November. Use our updated Electoral College Tie Finder to see what happens as you assign those states to Clinton or Trump.

If no candidate receives 270 electoral votes, the House of Representatives will pick the president. Each state delegation gets one vote, regardless of the number of congressional districts it has. 26 votes, representing a majority of the states, are required to win.

This in mind, it is useful to look at what party will control each state's congressional delegation in January, 2017. This is how it looks right now.

Republicans are very likely to control the majority of delegations in the new Congress. We discuss the above in more detail in this article about Electoral College Ties.  

Correction: An earlier version of this article incorrectly placed Montana in the 'Democratic or tied' category. Montana has only one congressional district, so a tie is not possible. The seat there is currently rated 'Likely Republican'; thus the state is also moved to 'Likely Republican' on the map.

The Commission on Presidential Debates has invited Hillary Clinton and Donald Trump to the first presidential debate scheduled for September 26th at Hofstra University. Likewise, the running mates of the two major party nominees, Tim Kaine and Mike Pence, were invited to the vice-presidential debate at Longwood University on October 4th.

Not invited were Libertarian Gary Johnson and Jill Stein. While both met two of the three main criteria for inclusion, neither was able to come close to the 15% polling threshold set by the Commission. Per the Commission's calculation, Johnson was at 8.4%, Stein 3.2%.

A new Texas Lyceum poll gives Donald Trump a six point lead over Hillary Clinton among likely voters in a head-head match-up. That's pretty much in line with other recent Texas polls. What caught our attention is that among all registered voters, it is Clinton with a four point lead.  That's a 10 point difference.

Most pollsters use a likely voter screen in the weeks leading up to the election, and that's what we use in our tables, when both are available. However, defining likely voters is a challenge for pollsters, as this 2012 article discusses. 

Perhaps this kind of difference reflects more passion for one candidate. At the same time, it could highlight an opportunity if one candidate's 'get out the vote' effort can significantly outperform on Election Day.