CEDAR RAPIDS, Iowa (Reuters) - Like many Iowans, Peggy Magner is still grappling with a weighty choice as the state’s first-in-the-nation nominating contest fast approaches: which Democratic candidate is best equipped to defeat Republican President Donald Trump in November.

FILE PHOTO: People hold signs as Pete Buttigieg, Democratic presidential candidate and former South Bend, Indiana mayor attends a campaign event in Cedar Rapids, Iowa, U.S., February 1, 2020. REUTERS/Eric Thayer

“It’s a hard thing, because we’re really not sure who can beat Trump,” the 70-year-old retired university professor said on Saturday in Cedar Rapids, where she was waiting for U.S. Senator Elizabeth Warren to take the stage at a rally. “All of us take this really seriously. I’ve been praying on it.”

Get the latest from the Iowa caucuses: here

Interviews with dozens of Iowans throughout the rural state pointed to plenty of votes still up for grabs once caucus meetings start on Monday. A recent Suffolk/USA Today poll said 13% of Iowa voters were undecided and 45% might change their mind. A Monmouth University survey released on Jan. 29 reported that nearly half of respondents might change their minds.

Several voters said the burden of their choice – the state’s verdict has historically had an enormous impact on the trajectory of the race – felt particularly heavy this year, with Democrats desperate to defeat Trump.

At a rally for former Vice President Joe Biden in Fort Madison, Marla Anderson, 66, said her heart told her to support Warren, but her head was leaning toward Biden, who she views as a potentially safer choice for the general election.

“I am just concerned about whether she can actually win. It’s beyond time that we get a woman in the White House, but not sure if she’s the right one,” Anderson, a former healthcare worker, said, before adding with a grin, “I may not know until caucus night.”

The leading candidates are criss-crossing the state this weekend in an all-out sprint, delivering their closing arguments on why they are the best choice to take on Trump this fall.

Liberal U.S. Senator Bernie Sanders touted his ability to expand the electorate, while Biden, a moderate, argued that only he is capable of bringing back disaffected swing voters who abandoned the party in 2016.

Meanwhile, Warren cast herself as uniquely positioned to “unite the party,” as new campaign signs at one rally read, by stitching together the liberal and centrist wings of the Democratic coalition. Pete Buttigieg, the 37-year-old former mayor of South Bend, Indiana, urged voters to embrace generational change. And U.S. Senator Amy Klobuchar pointed to her electoral victories in rural, Trump-supporting counties in Minnesota.

In public opinion polls, Sanders and Biden appear to be jockeying for the lead, with Warren and Buttigieg close behind.

In Iowa City, where Warren answered questions in front of a crowd of 900, Maggie Taylor, a 22-year-old who works in health policy, said she has narrowed her choice to between Sanders and Warren – but she has no idea how to decide.

She ticked off pros and cons for each – Sanders’ career-long commitment to progressive ideals versus Warren’s compelling backstory, Sanders’ ability to excite young voters versus Warren’s history-making potential as the first female president.

“I don’t know what’s going to help me make my decision,” she said.