So when will we know? Expect to see the GOP results first (maybe 8:30 or 9:00 pm ET), and if the GOP candidates are smart; they'll do their victory/concession speeches early, because competing with Obama and Clinton may be difficult as the night wears on. On the Dem side, results may take longer to calculate, particularly if the electorate is as different as some believe it might be.
The Los Angeles Times covers the last day of campaigning. "The costliest, most competitive race in the history of the Iowa caucuses wound to a cliffhanging finish Wednesday, as a crowded field of presidential hopefuls made their final pleas -- on the airwaves, in churches, in crowded gymnasiums -- on the eve of a vote that will lift some contenders and cripple the rest."
The AP's Mike Glover offers some hints at what to watch for tonight. In the GOP race, "[c]heck Plymouth County Thursday evening in remote northwest Iowa-chilly home of Blue Bunny ice cream and a hotbed of evangelical activists who could sway the first voting of the 2008 presidential campaign… Plymouth's county seat of Le Mars bills itself as "the ice cream capital of the world" because of the local dairy, but this year in politics "that's Huckabee territory," says David Roederer, a veteran activist who's been advising John McCain's Iowa campaign this ear. A big turnout could be a sign that evangelicals-accounting in past cycles for up to 40 percent of the Republican caucus vote-are delivering for the one-time Baptist minister."
Meanwhile, "Democrats might get an early take on their caucuses from Newton, a company town battered by the closing of Maytag Corporation's big plant… It's a Democratic town of about 15,000 and used to be the home for Maytag, an iconic Iowa manufacturer that has shut down and tossed thousands out of work. John Edwards has used that closure as a symbol for his populist message that rich and powerful businesses are out to exploit working families. He even used a former Maytag worker as the voice for his closing television commercial. Hillary Rodham Clinton and Barack Obama have contested the town, and it could be an early barometer."
"All eyes on Iowa" is the headline on the front page of the Boston Globe with pictures of Huckabee playing the guitar in front of a laughing Kevin Eubanks on the Tonight Show, Romney shaking hands, Clinton, Obama and Edwards speaking. The Globe writes, "For GOP, a test today of whether money talks."
National Journal's Ron Brownstein breaks down the message pitches of the Big Three Democrats.
NBC's Mark Whitaker shares these questions with First Read: If Obama wins, how important will it be that the Iowa caucuses were held so early in January, when college kids are still on vacation? Instead of being back at school, will they now be free to kill a whole evening exercising their democratic rights? On the other hand, if he doesn't win, won't it be the latest and most definitive proof yet that the "youth vote" always disappoints?
For those looking for good polling data heading into tonight, check out pollster.com.
"Thousands more Iowa independent voters are expected to turn out for Democratic presidential candidates than Republicans at today's Iowa caucuses," the Des Moines Register writes.
The New York Times' Leibovich: "It's the groggy, nerve-sizzling season on the trail, and forget the attack ads and last-minute scrapping. Any candidate will attest that the epic fight now is against sleep deprivation, the gaffe-inducing monster that looms over every campaign in its final hours."
McClatchy calls this "the longest, costliest election run-up in American history, the first since 1920 with no heir apparent in either party. Both parties are eager to turn the page on the George W. Bush era -- particularly Democrats angry about the Iraq war, but also Republicans unhappy about such issues as illegal immigration."