Tuesday's precinct caucuses have given the first signs of who has support from Minnesota Democrats and Republicans in this year's gubernatorial race.

With Gov. Mark Dayton retiring this year, both major parties have to pick a new candidate to run for his office.

The caucuses on Tuesday evening ended with a straw poll, with party supporters in attendance giving an early indication of who has their support.

For the Democrats, U.S. Rep. Tim Walz (CD-01) led the way with three-quarters of precincts reporting, gaining 30.8 percent of the vote ahead of state auditor Rebecca Otto on 20.1 percent.

For the Republicans, Hennepin County Commissioner Jeff Johnson led the way, ahead of "undecided" and former Republican Party Chairman Keith Downey.

But it doesn't mean they'll get the nomination

Straw polls are optional for caucus-goers and as this article by data company IQS Research points out, are not reliable indicators of the eventual winner.

They are however useful for weeding out the weaker candidates – some of whom drop out based on the results of a straw poll – as well as help stronger candidates fine-tune their campaigns.

History shows us that the winners of caucus straw polls don't always go on to win the nomination.

In 2014, Marty Seifert led the Republican straw polls to challenge Gov. Mark Dayton, while eventual winner – Jeff Johnson again – was in third.

Four years earlier in the 2010 precinct caucus, MPR report Brian Bakst recalls that R.T. Rybak won the straw poll, while eventual nominee Mark Dayton wasn't even on the ballot.

The 2010 example could be repeated for Minnesota Republicans in 2018, given that two arguably strong candidates – former governor Tim Pawlenty and current House Speaker Kurt Daudt – are considering runs for governor.