海角大神

It鈥檚 caucus day in Iowa, and the crisp air is crackling with anticipation. After all the months of organizing, fundraising, speechifying, advertising, and polling, actual voters will finally have their say.

Iowa will settle nothing, but the results will still matter 鈥� a lot. The winners will head into the New Hampshire primary on Feb. 9 with momentum, while those at or near the bottom will be hard-pressed to keep going.

Both parties鈥� .聽Much will depend on turnout. Do the big, enthusiastic rallies for the two populist iconoclasts 鈥� Donald Trump and Sen. Bernie Sanders 鈥� signal a willingness to show up at a caucus, or will the more traditional campaigns, like those organized by Sen. Ted Cruz and Hillary Clinton, carry the day?

Caucuses, after all, are not like primaries. Voters must show up at their precinct site by a specific time 鈥� 7:00 p.m. CST 鈥� prepared to sit through speeches before they can vote. Chilly temperatures and impending snow could keep people away. The higher the turnout, the greater the chances for Mr. Trump and Senator Sanders, analysts say.

Here are three other factors to watch:

First-timers and late deciders.聽Polls are 鈥渁 snapshot in time,鈥� as those in the business like to say. Voters who decide late, or change their minds at the last minute, can make for some upsets once the actual votes are counted. First-time caucus-goers can also be unpredictable; after all, they don鈥檛 have a history of turning out.

Take Mike P., a retired Home Depot worker from Waterloo, Iowa, who has never caucused before, but is planning to this year. He says he鈥檚 worried about national defense after seven years of President Obama.

鈥淪o far, I鈥檓 with Marco Rubio,鈥� says Mr P., who declined to give his last name. At first, he backed Trump, but decided in recent days that the brash billionaire is 鈥渏ust too much.鈥� So here he is, at the Florida senator鈥檚 event Sunday afternoon at the University of Northern Iowa in Cedar Falls. He says he likes the 鈥渋ntensity鈥� in Senator Rubio鈥檚 eyes when he speaks, and 鈥渃an see that he鈥檚 smart and honest.鈥� But after the event, he still won鈥檛 say if he鈥檚 firmly with Rubio.

Another fence-sitter at the Rubio event in Cedar Falls is realtor Christopher Haley. On Saturday, he saw Trump, and after seeing Rubio on Sunday, he said he was leaning toward Trump, because he鈥檚 outside the Washington establishment.

Mr. Haley likes the fact that Rubio came up through the tea party movement in Florida. 鈥淏ut lately, we鈥檙e thinking even more outside than that,鈥� says Haley, his wife at his side. 鈥淲e respect Donald Trump for his business dealings, and we think he has a good view of the world.鈥�

But Haley says he wants to check out one more candidate: Senator Cruz of Texas, polling second in Iowa behind Trump.

The latest Des Moines Register/Bloomberg poll, released Saturday night, found that 9 percent of likely GOP caucus-goers had yet to make a choice, and an additional 36 percent could still change their minds before Monday night. In a tight race, that volatility could make for some surprises.

Expectations.聽Both Trump and Cruz have set high expectations for themselves. Trump鈥檚 life in business and now in politics is all about 鈥渨inning.鈥� Just a few weeks ago, Cruz appeared to be heading toward victory in Iowa, with strong support from Evangelicals. And Cruz鈥檚 campaign has been touting his extensive turnout operation in Iowa and other early states, organizing dormitories of volunteers called 鈥淐amp Cruz.鈥�

Rubio has been quieter about his operation, and thus if he performs better in Iowa than the polls indicate 鈥� had him in third place with 15 percent聽鈥� that would give him momentum heading into New Hampshire. Trump is far ahead in the polls there, but second place is up for grabs. A breakout moment for Rubio in Iowa could be enough to hand him second place in the Granite State 鈥� and a shot at seeing mainstream Republican voters coalesce around him.

鈥淓lectability鈥� has been a theme in Rubio鈥檚 closing argument to Iowa voters. 鈥淏eing angry is not a plan,鈥� he says in Cedar Falls, alluding to Trump. Later, he takes aim at Mrs. Clinton.

鈥淗illary is not qualified to be president of the United States,鈥� he says, referring to her use of a private e-mail server while secretary of State. 鈥淪he thinks she鈥檚 above the law.鈥�

鈥淚f I鈥檓 the nominee, we win,鈥� he says.

The rules of the game. Iowa Republicans hold a secret ballot at their caucuses, but the Democrats don鈥檛. Under their system, caucus-goers physically stand in a part of the room designated for their candidate. If a candidate does not reach 15 percent of the total, he or she is declared 鈥渘onviable,鈥� and his or her voters must pick a second choice.

Thus, supporters of former Gov. Martin O鈥橫alley, who is polling in low single digits among Democrats, may well have to go with their second choice, either Clinton or Sanders. That group of 鈥渟wing caucusers鈥� could be critical in a close precinct that selects an odd number of delegates.

But the Clinton campaign is hedging its bets, and has an app that would solve the problem in a different way: , the app would 鈥渃ount the number of supporters for each candidate and send caucusers to O'Malley's side if it keeps Sanders from winning an extra delegate.鈥�

The Sanders campaign is counting on the passion of its volunteers to carry their candidate over the finish line. On Sunday, that was on full display in Marshalltown, Iowa, when Sanders paid a visit to his campaign鈥檚 field office there.

Sanders was mobbed as he walked down the main street. When he entered his campaign鈥檚 downtown storefront, the windows quickly steamed up as volunteers and staff packed inside to see the man. Cheers rang out as he rallied his troops.

Among those standing outside were a group of volunteers who had driven in from Tennessee a few days before. Christina Besh of Chattanooga is taking vacation time from her job as a nurse at a Veterans鈥� Administration clinic to help Sanders.

鈥淚 left my husband and kids at home,鈥� says Ms. Besh. 鈥淚 feel kind of guilty, but they told me, 鈥榊ou鈥檒l never forgive yourself if you don鈥檛 do this.鈥� 鈥�