WAUKEE, Iowa — Amy Klobuchar sounded like a candidate with an eye on the clock.

The senator from Minnesota had been on the road all day Sunday, starting the morning in Davenport, where she had awakened to discover she’d won the endorsement of the local newspaper, the Quad-City Times. She had held a town hall in tiny Marion and then driven two hours to Des Moines, where she appeared at two more events back to back.

By the time Klobuchar rolled up here, in her bright green campaign bus with “Amy” written on the side in giant white letters, it was well after 7 p.m. on what was said to be the coldest night of the year in Iowa so far. The wind chill was 20 below zero and dropping, and as voters arrived, their shoes crunched on patches of snow and ice that covered the street and sidewalk outside, slick remainders of the winter storm that had snarled candidate travel around Iowa over the weekend.

But a little weather has never stopped Klobuchar. She famously launched her bid for the presidency in the midst of a Minnesota snowstorm — prompting taunts from President Trump, who said she looked like a snowman. And when an ice storm crippled much of southeast Iowa two weeks ago, Klobuchar refused to cancel her events. “A little sleet doesn’t scare me,” the senator told reporters.

But there was something even bigger than Mother Nature that she couldn’t challenge: the impending kickoff of the impeachment trial of Trump in Washington. Klobuchar and the other sitting senators in the presidential race — Bernie Sanders (I-Vt.), Elizabeth Warren (D-Mass.) and Michael F. Bennet (D-Colo.) — are all jurors required to be there, disrupting their campaigns a little over two weeks before Iowa’s first-in-the-nation caucuses on Feb. 3.

“I think you all know that I'm going to have to be leaving actually tomorrow night and going back to the impeachment hearing,” Klobuchar said, as she opened her event here before about 150 voters. “We get a lot of questions about, well, how are you going to keep running? I always tell people that I'm a mom and I can do two things at once.”

But you couldn’t miss the disappointment in Klobuchar’s voice. The impeachment trial comes as things have finally seemed to be going her way. Although she is still running behind the four candidates who have led the polls here for months, including Sanders, Warren, former vice president Joe Biden and former South Bend, Ind., mayor Pete Buttigieg, there have been signs of hope for Klobuchar.

She had landed notable endorsements from prominent local Democrats, including some who had jumped to her after rivals like Sen. Cory Booker (N.J.) dropped out. (Later Sunday, she would claim, along with Warren, a split endorsement from the New York Times.) She had raised enough money to run television ads and expand her ground game in Iowa. And her crowds were growing in size, full of undecided voters who have said they are considering her as a younger alternative to Biden, whose age is concerning to many voters here.

At events, especially in rural, more conservative areas of the state, some Iowans have spoken of a dream ticket of Biden and Klobuchar — a subject that once again came up in conversations with voters who turned out to hear the senator from Minnesota speak Sunday night.

“I like them both,” said Michael Bylund, 70, of Waukee, an undecided voter who came to see Klobuchar with next-door neighbor Evelyn Turk, 81.

“We were just talking tonight about how if we knew who the running mate would be, that would help us make some decisions,” Turk said.

Both women said they were anxious to support someone who can defeat Trump, but were struggling to decide who to caucus for. They worried about Biden’s age, but they felt he was strong against Trump. Buttigieg was too young, they said. Warren and Sanders, they felt, were too much to the left to win broad support.

And as much as she liked Klobuchar, Turk worried about voters rejecting the idea of a female president. “I hate to say this, as a woman, but I still am not sure about a female president. I just don’t know how many votes she would get,” she said. “It’s just so hard. That’s why it would be nice to know what she’s thinking about [for] a running mate. Or what any of them are thinking, because then you could figure out a little better how strong they might be against Trump.”

Onstage, Klobuchar delivered her usual stump speech, once again making the case that she, as a moderate senator from a Midwestern state with a record of working across the aisle and winning support from both urban and rural voters, is the strongest candidate against Trump. She vowed to be a president for rural America, at one point telling an unusual story about how her husband, as a child, was sometimes left behind at gas stations by his parents because he was quieter than his three brothers.

“I will never leave the Midwest behind at the gas station, because Iowa and the Midwest is not flyover country to me,” she said, as the crowd laughed.

Klobuchar warily eyed a campaign aide who had walked to the front to signal that it was time to start wrapping up. She had a plane to catch to South Carolina, where, after criticism, she had decided at the last minute to join her rivals at an event honoring the Rev. Martin Luther King Jr. on Monday morning before returning to Iowa. “Long story,” Klobuchar said.

Then it would be back to Washington on Monday night, for who knows how long. Klobuchar said she would rather be in Iowa. “I would like nothing more,” she said.

She pointed to her intense campaign schedule here in recent weeks, including a three-day stretch where she hit 27 counties — wrapping up her quest to hit all of Iowa’s 99 counties. “I would love to do 10 counties a day, but I am going to be there,” she said of Washington.

Her campaign was planning to bring out surrogates to fill her absence, including her husband and daughter, and a litany of elected officials from Minnesota. But what she really needed, Klobuchar told the audience, was for them to come off the bench and commit to her.

“I just ask you to help me, too, to sign those commit-to-caucus cards. I know there’s two weeks left for you to decide,” she said, her voice a little more pleading than usual. “Sign those cards. … Join our campaign.”