It’s just about time for the speculation, "expert" opinion and analysis about what might happen in the 2014 election to come to an end. After 5 p.m. Eastern time preliminary exit poll results will start to trickle out and we'll hear directly from actual voters about their choices and, as importantly, why they made them.

Here are five key factors to watch from tonight’s exit polls. Check in early and often to our election live blog for exit poll coverage and follow us on twitter @PostPolls.

1. Turnout and voting for key Democratic groups

Democratic campaigns have focused on turning out young people, minorities and unmarried women in numbers roughly equivalent to presidential year turnout. Each of these groups delivered big vote margins for Barack Obama in 2008 and 2012. But they also failed to turnout at nearly the same rates in the 2010 midterm elections. Will 2014 look more like 2010 or 2012 for these key groups?

History tells us that the drop-off in turnout from presidential to midterm years is very consistent across all voting groups. But it was especially bad for Democratic-aligned groups in 2010. This interactive chart clearly demonstrates the falloff.

In 2008, 51 percent of voters age 18-29 turned out to vote. But that plummeted to 23 percent turnout for this age group in 2010 according to Census voter trends. What’s worse for the Democrats is the fact that they went from supporting Obama by a whopping 34 point margin in 2008 exit polls to just a 13-point margin for Democrats in 2010.

2. President Obama

History suggests that midterm elections are chiefly a referendum on the president’s party, and the exit poll will provide a clear indication of Obama’s impact on the vote. Four years ago, 55 percent disapproved of the Obama and more voters said they cast their congressional vote to express opposition to Obama than to support him (37 to 23 percent). That margin was similar in a Post-ABC poll released last week, with 31 percent of likely voters saying opposing Obama is a factor in their vote but just 16 percent calling it an expression of support.

The new data will also shed light on how many more Obama opponents turned out to vote than Obama supporters. In 2010, Obama disapproval was 10 points higher in the exit poll than in the final pre-election Washington Post-ABC News poll of all U.S. adults (45 percent). This year, Obama is less popular overall, with 51 percent disapproving.

3. Trends in partisanship

No other indicator is as predictive of vote as partisan identity -- not gender, age, race, ethnicity, income or anything else -- and the partisan composition of the electorate for the past several elections has fluctuated widely between midterm and presidential years.

In 2004, when George W. Bush won re-election, the number of Republicans in the electorate equaled the number of Democrats, an unusual partisan parity. But by 2006, when Democrats won control of the House and Senate, Democratic identification edged ahead of Republican identification by 2 points.

When Obama was first elected in 2008, Democrats outnumbered Republicans by seven points in exit polls. But that gap was erased in the 2010 midterms when Republicans won in a wave election. Two years later when Obama easily won re-election, the partisan gap of six points returned.

4. The economy and the anti-Washington mood

The economy has been the top voting issue in every national election since 2008, and pre-election polls from the Washington Post and ABC News suggest it is the top issue again. What’s different this time is that objective measures indicate a healthier economy than in the past six years.

Will an improving economy translate to better results for Democrats? This seems unlikely, as falling unemployment and steady job growth have not shaken the public’s basic view that the economy is still in bad shape. The latest Post-ABC poll finds more than twice as many people rate the economy negatively as positively, and just as many see the economy as getting worse (31 percent) as say it is getting better (28 percent).

Beyond the economy, two in three say the country is off on the wrong track in the latest Post-ABC poll, the same as four years ago. That survey also found 60 percent saying they can’t trust the government, no different from the anti-DC mood during the government shutdown in October 2013.

5. How big a role racial and ethnic minorities play in key states

Turnout among African American and Hispanic voters may be critical in several key Senate states, and the exit poll provides a rough gauge of the role they play. Democrats are hoping significant African American turnout will boost Sen. Kay Hagan in North Carolina and Michelle Nunn in Georgia. And in Colorado, Sen. Mark Udall may need outsized participation and vote support from Hispanics to come for behind and win.

It’s worth noting the exit poll and other data sources don’t always agree on the share of the electorate that are white, black, Hispanic or other races. A 2007 study found the exit poll tends to report a higher share of minorities than voter records or the Current Population Survey indicates. So, it’s best to stick to apples-to-apples comparisons for exit polls and other sources, and not to over-interpret 1-2 percentage point changes from year to year.

For exit poll coverage tonight, follow the Post's election live blog and follow us on twitter @PostPolls.