Check back throughout the day as we update this story with key moments and new developments on the campaign trail.

Joe Biden

Biden is moving more aggressively on his Democratic rivals as the campaign enters its final stretch.

Calling his plan for health care “more real” than other candidates’ more expansive proposals, the former vice president said Thursday night, “The one thing I don’t think we can do is go out in a race against Trump and say things that turn out not to be able to be done.”

“He will just eat us alive," Biden continued.

Biden had been doing just about everything he can to fast-forward to the general election, spending much of Thursday talking about Trump’s arrival in Des Moines and redoubling his emphasis on electability in the final stretch of the Iowa campaign

But Biden is also aware that the caucus Monday is “going to be close.” And by late Thursday, he was rebuking the competitors to his left.

Three public events in a day is not a particularly grueling schedule, but that is the one Biden will keep again Friday in eastern Iowa, with events in Burlington, Fort Madison and Mount Pleasant.

-David Siders

Pete Buttigieg

Buttigieg is taking his campaign to new heights on Friday — literally. He's chartering a plane to get from Sioux City in the morning, nestled on the western border of Iowa, to Davenport by the evening, bordering the eastern side of the state. It's 350 miles and 5 hour and a half hour drive apart, but a plane means Buttigieg can add in another two town halls -- one in Council Bluffs ad one in Clinton -- in between.

He's hitting up mid-size cities on both sides of the state, drawing on the suburban communities that surround them. It's an aggressive schedule that Buttigieg can keep up, while some of his top competitors are stuck on Capitol Hill in impeachment proceedings.

Buttigieg ratcheted up his hits on Thursday, by calling out Bernie Sanders and Joe Biden by name. Rather than veiled shots, he's opting for explicit contrast. I'll be watching whether he continues doing that, particularly as we wind down to the final days ahead of the caucuses. Clearly, Buttigieg feels the need to step up the pressure, but will he keep it up? And will it make a difference? We won't know that until Monday night.

-Elena Schneider

Amy Klobuchar

Klobuchar will be in Washington for at least one more day on Friday, while the two candidates she's competing with the most for supporters — Biden and Buttigieg — get Iowa mostly to themselves. As Klobuchar’s daughter, Abigail Bessler, and other surrogates made their way through Iowa on Thursday, Klobuchar said she wouldn’t give up on trying to get witnesses in the impeachment trial.

"It will not be a fair trial if we don't have witnesses," Klobuchar said on CNN. "I just want to get the witnesses."

Thursday evening, Olympic curling coach and Minnesotan Phill Drobnick touted Klobuchar’s ability to win in Trump districts in her home state during a hotdish party in Prole, just outside of Des Moines — a theme her campaign is hammering home in the final days.

“The electability argument is what we're seeing on the ground as one of the most effective reasons why people are finally making their decision and coming on board,” Norm Sterzenbach, Klobuchar’s Iowa caucus adviser, told reporters at a Bloomberg News breakfast Thursday.

Two Minnesota elected officials, Duluth Mayor Emily Larson and St. Paul Mayor Ross Wilburn, are scheduled to campaign in Ames, Iowa for Klobuchar on Friday, while Bessler will join them later in the day for a meet and greet with voters in Indianola.

-Laura Barrón-López

Bernie Sanders

One of the feature acts of “Bernchella” debuts Friday.

Bon Iver, the indie band, will perform in Clive, Iowa as part of Sanders’ traveling celebrity surrogate tour. The Vermont senator, meanwhile, will be in Washington for the impeachment trial, itching to get back on the campaign trail soon. (Sanders' wife Jane said Thursday night that Bernie will "hopefully get to Iowa sometime this weekend, but we don't know.")

Whether or not the senator makes it to Iowa, the Sanders campaign will hold nine events in the state Friday: Reps. Ilhan Omar and Rashida Tlaib, along with Congressional Progressive Caucus co-chair Pramila Jayapal, will kick off canvass launches in Des Moines, Council Bluffs, Greenfield and elsewhere. Jane Sanders will speak with small business owners and join filmmaker Michael Moore for a pair of town halls.

The goal of the Bon Iver show? Juice turnout, especially among young people.

Meanwhile, Sanders’ campaign is also trying to boost him among seniors, with whom he struggles, with a TV ad launched Thursday in Iowa that highlights his history defending Social Security. Though it doesn’t mention him by name, the ad is also implicitly about Biden, who has entertained cuts in the past. Biden and Sanders have been fighting over their records on the issue.

-Holly Otterbein

Elizabeth Warren

Warren will spend most of Friday in Washington as a juror in the impeachment trial — again. Warren has repeatedly said that the trial is more important than politics, but she has also expressed frustration that she is not in Iowa for the final stretch before Monday’s caucuses. The campaign has planned events only to have to send surrogates in Warren’s place.

That will be the case again Friday. “Due to the schedule for impeachment in the U.S. Senate, Elizabeth Warren’s previously advised events in Sioux City and Ames have been changed to get-out-the-caucus rallies with Congresswoman Katie Porter and John Norris in Sioux City and Congresswoman Ayanna Pressley and John Norris in Ames,” the campaign told reporters late Thursday.

Warren’s campaign, perhaps optimistically, is also planning for a big nighttime rally in Des Moines featuring the senator herself as well as Porter, Pressley and more of her surrogates. If she makes it, it will be her first time in the state since last weekend as she has been held up in D.C. I’ll be curious to see if she emphasizes electability even more on the stump--as her campaign has been doing in recent weeks. The campaign largely avoided process-oriented arguments last year but have ramped them up in the final weeks before voting as voters have expressed concern about her chances against Donald Trump in November.

Her latest polling in Iowa shows her in striking distance of victory but sliding slightly. Still, the campaign has invested tremendous money and resources into their organizing team and are counting on it to inch ahead a few points and overtake some rivals.

-Alex Thompson