Election Day is finally here in Alabama's U.S. Senate race.

Voters are deciding between Democrat Doug Jones, a former prosecutor, and Roy Moore, the former state Supreme Court chief justice. Moore, popular with evangelicals in the state, has been embroiled in controversy. Multiple women have accused Moore of sexual misconduct and assault; many of them were teenagers at the time they say the misconduct took place. Moore denies any wrongdoing.

Nonetheless, Moore's candidacy — controversial before the allegations — has driven a wedge through the GOP. Establishment Republicans are on one side, and President Trump and his former chief strategist Steve Bannon are on the other. Whatever happens on Tuesday night, there will be consequences felt from Birmingham to the Beltway.

Here's what to watch and what the results could mean:

What time do polls close and when do we expect results?

Poll close at 8 p.m. ET. Given how close the race is expected to be, don't expect results for a while after polls close.

Keys to the race: How many Republicans stay home?

The president seems to believe Moore's denials. Trump explicitly endorsed Moore and campaigned for him in neighboring Pensacola, Fla., which is in the Mobile, Ala., media market. But other Republicans disagree.

The state's senior senator, Richard Shelby, for example, says that he "couldn't vote" for Moore and wrote in another Republican. The question is how many other Republicans will also make that determination.

For Jones to win, a lot of them will have to do it. Trump won this state after all, 62 percent to 34 percent in 2016 and won more votes than any presidential candidate (a little over 1.3 million).

One liberal group is running a Facebook ad encouraging Republicans to Roll Tide and write in Nick Saban, the larger-than-life coach of the University of Alabama football team.

Does Jones fire up black voters?

Arguably bigger than whether Republicans stay home is whether Jones can fire up black voters.

Off-year special elections can be particularly difficult for Democrats to turn out minority and young voters. But turning out black voters is key for Jones. African-Americans make up about 27 percent of Alabamians (and about 23 percent of registered voters).

In 2008, when Barack Obama was on the ballot, black voters voted in outsize numbers, making up 29 percent of voters and leading Obama to receive the most votes for any Democratic candidate in Alabama's history (more than 813,000).

To put the significance of the black vote into perspective: Roughly three out of every four votes Obama got were from black voters.

And Jones has a story to tell. He prosecuted Ku Klux Klan members for the 1963 bombing that killed four little girls in a Birmingham church. Last month, he called it the "most important thing I have done."

Jones has campaigned with Sen. Cory Booker, D-N.J., and Obama recorded a robocall for him.

NPR correspondent Debbie Elliott, who lives in Alabama and has been covering the state for more than 30 years, says to watch the cities (Jefferson County, where Birmingham is, and Montgomery made up 28 percent of Obama's 2008 vote total), but also Macon County (Tuskegee) and Dallas County (Selma) for signs of how much Jones is winning black voters.

Elliott also reports, though, seeing Jones signs pop up in rural areas, where Trump signs were as well. Does Jones cut into margins in Madison (Huntsville), Mobile or Tuscaloosa counties — or even strong Trump counties, like Cullman, where Jones was campaigning last week?

Of course, African-American voters can only take a Democrat so far in Alabama. Obama still lost 60 to 39 to John McCain.

The consequences: What if Moore wins?

A Moore win puts Republicans in a pickle.

Do they move to expel the senator whom the grass roots just picked and possibly cause an uprising in the base? Or do they let him stay and further risk credibility on the issue of sexual misconduct?

If Moore wins, it will draw a bright line between the parties. Democrats would try to paint the party as too extreme and be more than happy when Moore speaks out in the hallways of Congress, forcing GOP members to have to support or denounce his statements — be it on race or on people who are gay, lesbian or transgender. Democrats would hope that by highlighting Moore being accepted into the GOP caucus, they could trigger buyer's remorse in 2018 among Obama-turned-Trump voters.

On the other hand, Republicans can try to dismiss the allegations against Moore as politically motivated (as Moore himself has done) and old, and hope to bait Democrats — again — into a culture war. It's something the Democratic base can't seem to resist. Instead of running against the tax bill or health care or talking about how they plan to bring back a fairer economy that works for everyone, Democrats would be at risk of repeating 2016.

What if Jones wins?

It would send shock waves. Democrats would be ecstatic. First, the Senate would narrow to just a two-seat Republican majority, 51-49, making legislative success that much harder for Trump and Republicans. Democrats would also suddenly see a narrow window open to possibly taking back the Senate next year.

And yet, some Republicans would privately breathe a sigh of relief. The Senate wouldn't have to contemplate expulsion — and the GOP wouldn't have to worry as much about being painted as complicit.

A Jones win would also give the anti-Moore, anti-Trump Republicans some ammunition for their warnings that the party needs to moderate or lose — even in places like Alabama. It would indicate nowhere is safe and give Republicans what they hope is enough time — months before the first 2018 primaries — to pick candidates who can win.

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