MINNEAPOLIS — Minnesota voters on Friday became some of the first in the country to cast ballots in the presidential primaries as early voting began for the state's Super Tuesday contest.

Eligible Minnesota voters can now vote at county courthouses across the state, and early voting stations in some cities, and they can also request absentee ballots for the March 3 primary. But the votes won't be counted until primary night.

Fifteen candidates are on the Democratic ballot, even though three already have quit the race. The GOP ballot lists only President Donald Trump, though write-in votes are allowed. It's Minnesota's first presidential primary since 1992 after years of using precinct caucuses to kick off the process of selecting national convention delegates.

Early voters can retrieve their ballots and change their votes up to a week before that date for any reason, such as their favorite candidate dropping out.

With temperatures hovering around zero degrees, Davis Senseman and a handful of friends camped out in a rented RV outside a Minneapolis polling station overnight in hopes of becoming among the first to vote.

Some states, including New Hampshire, started accepting absentee ballots earlier for voters who can't make it out on their states' actual primary day. But Minnesota allows anyone eligible to vote to do so early.

Senseman told Minnesota Public Radio they support Democratic Sen. Elizabeth Warren.

"I think she's building a hugely broad coalition," Senseman said. "This is an RV full of Warren supporters."

Supporters of Minnesota Sen. Amy Klobuchar's presidential campaign had early voting events scheduled across the state Friday. And Klobuchar was due to appear at a rally Friday night at the First Avenue nightclub in downtown Minneapolis with Gov. Tim Walz, Sen. Tina Smith and U.S. Rep. Angie Craig.

Meanwhile, U.S. Rep. Ilhan Omar held two get-out-the-vote rallies in Minneapolis for Sen. Bernie Sanders.

At a midday event at the University of Minnesota, Omar encouraged students to bring friends and classmates to the polls to vote for Sanders in hopes of repeating the Vermont senator's win in the 2016 Minnesota caucus, the Star Tribune reported.

"We know how important it is for us to be in every corner, talking to everyone ... making sure people are getting out and voting," she said.

In Duluth, Ashlie Castaldo, her early ballot for Klobuchar.

"She's pragmatic but has a sense of vision," Castaldo told MPR, adding that if Klobuchar exits the race, she would take just about any Democrat as the nominee to face Trump .

Voters must request either a Democratic or Republican ballot, and their names will be shared with the state's major parties.