Paul Gazelka staffer Angel Zierden instructed volunteers where to hang the candidates signs and banners Thursday in Rochester as the stage was being prepared for the Minnesota State Republican Convention. (Glen Stubbe, Star Tribune/The Minnesota Star Tribune)

Donald Trump's endorsement is helping shape Republican races across the country, but the former president hasn't picked a side in the party's unsettled race for Minnesota governor.

"He hasn't seen a compelling reason to reward or punish," said David Sturrock, a former Minnesota Republican Party official and a political science professor at Southwest Minnesota State University. "He's big on both."

The power of Trump's endorsement is casting a long shadow over GOP races across the country. While author J.D. Vance won a contentious Ohio Senate primary after getting the former president's endorsement, Trump also supported a controversial candidate for governor in Nebraska who lost a primary earlier this week after being accused of sexual assault.

In races yet to be decided, the former president picked a side in a competitive Pennsylvania Senate primary and backed a Republican challenger against GOP Gov. Brian Kemp of Georgia.

Trump's absence in Minnesota isn't keeping GOP contenders from trying to attach themselves to him before Republican delegates gather in Rochester this weekend to make an endorsement for governor at the party's state convention.

Minnesota Republicans haven't won a statewide race since 2006, when Tim Pawlenty was re-elected to the governor's office. While Trump continues to spread false claims that the 2020 election was rigged, and while he was impeached by the U.S. House for inciting the Jan. 6 insurrection, he holds significant influence over Republicans nationally and has shown signs he could seek the White House again in 2024.

In an e-mail blast last month, state Sen. Paul Gazelka said he "defended President Trump vigorously on the campaign trail in 2020."

"It was the right thing to do politically for the cause of re-electing my caucus' majority. And it was the right thing to do morally," wrote Gazelka, a former Senate Majority Leader.

State campaign finance records also show Republican governor candidate Kendall Qualls has paid thousands to a firm that lists Trump's 2020 campaign manager as a founding partner.

GOP gubernatorial candidate Neil Shah said a Trump endorsement "would certainly help."

"There's a significant amount of the base that's going to look at that Trump endorsement as being very valuable," said Shah, a dermatologist who's never run for office before.

Trump has never carried Minnesota in a competitive race. He finished third in the state's caucuses in 2016 before losing to Democrat Hillary Clinton by about 1.5 percentage points in the general election. After running uncontested in the state's 2020 primary, Trump lost Minnesota to Democrat Joe Biden by about 7 percentage points in the November 2020 election.

Marty Seifert, a past candidate for governor and former Minnesota House leader, said he didn't know if a Trump endorsement would be an asset or a liability in a general election.

"I think they're more interested in the future than the past, frankly, and they want a candidate who could win the election," Seifert said of his fellow GOP delegates.

Republicans are meeting in Rochester on Friday and Saturday to make their picks in statewide races. DFLers from across the state will do the same the following weekend.

Election concerns have been a common theme among GOP candidates who have spent months courting voters at rallies, caucuses and conventions. Candidates for statewide office have called for additional election measures such as voter ID requirements, and many have danced around the question of acknowledging that President Biden won the 2020 election.

Support for law enforcement and a tougher approach to rising crime have also been top issues for gubernatorial candidates, as has opposition to now-expired pandemic-related government mandates. Some delegates have said pandemic and education-related concerns — around parental control, school choice and critical race theory — have prompted a number of people to get involved with the GOP for the first time.

Trump has also stayed out of the upcoming special Republican primary in the First Congressional District despite easily winning the area in both of his races for president. Early voting began weeks ago for the May 24 special primary as candidates seek to serve out the rest of the late GOP Rep. Jim Hagedorn's term.

Republicans in the race are trying to emphasize their Trump bona fides to voters. Jennifer Carnahan, Hagedorn's widow who is seeking her husband's seat, tweeted in March about visiting Trump's Mar-a-Lago. While a photo of Hagedorn, Carnahan and Trump is a fixture on the main page of her campaign website, she downplayed the fact that the former president hasn't endorsed in the race so far.

"I don't think it shows anything to be honest," Carnahan said. "I think maybe there's other places he's looking at. I think it is a crowded field. I don't know; I am not the president."

The online campaign bio for fellow Republican candidate Brad Finstad notes early on that he "is proud to have served as President Donald J. Trump's State Director for USDA Rural Development in Minnesota," and lists one of his values as being "Pro-Trump."

And GOP state Rep. Jeremy Munson's congressional campaign website touts his support for the "America-First agenda" before featuring a photo of Munson at a Trump event in which the former president is visible.

"Trump's endorsement in our race would certainly show who the real conservative is," Munson said.

Staff writer Jessie Van Berkel contributed to this report.