This is Minnesota's first presidential primary since 1992.
Amy Klobuchar's abrupt withdrawal from the presidential race gave front-runner Bernie Sanders a sudden opportunity to lock up her home state on Super Tuesday.
Sanders, who easily won Minnesota's caucuses in 2016, has a large and motivated progressive base in the state, offsetting Klobuchar's presumed home-field advantage in a race that was increasingly seen as tight before she dropped out Monday. Her departure followed the weekend exit of fellow moderate Pete Buttegieg.
Sanders also had a fortuitously timed last-minute rally in St. Paul on Monday night, which was scheduled days before Klobuchar quit the race. He also had backing from two progressive stars with national followings — U.S. Rep. Ilhan Omar and Attorney General Keith Ellison.
Klobuchar and Buttegieg endorsed Joe Biden as moderates moved to blunt Sanders' rise. Biden was fresh off a big win in South Carolina on Saturday but had little campaign organization in Minnesota and hadn't spent significantly in the state. But Mike Bloomberg, also crowding the moderate lane, spent heavily on TV ads for weeks in the state as part of a Super Tuesday strategy that bypassed the earliest-voting states. Elizabeth Warren was Sanders' rival among Minnesota progressives.
Minnesota had 75 national convention delegates up for grabs.
It's Minnesota's first presidential primary since 1992, and the first that's binding on both parties since 1956. The state ditched a caucus system after 2016 saw long lines and chaotic gatherings in some places, but the primary system set up by state lawmakers has raised privacy concerns that may dampen turnout. Voters' names and party preferences must be reported to the state's major parties.
President Donald Trump had the Minnesota GOP primary ballot to himself after party leaders decided not to list any Republican challengers, though write-in votes will be allowed.
Early voting began Jan. 17. As of Friday, election officials had accepted over 57,000 Democratic and nearly 9.000 Republican ballots. The early ballots cast for Klobuchar must be counted but became irrelevant once she left the race.