Wisconsin Treasurer Sarah Godlewski dropped out of the state's Democratic U.S. Senate primary Friday, the third candidate to bow out this week, making Lt. Gov. Mandela Barnes the clear frontrunner to face Republican Sen. Ron Johnson.

The race in battleground Wisconsin, which Donald Trump narrowly won in 2016 but lost by a nearly equal number of votes in 2020, could determine which party holds majority control in the 50-50 Senate. Johnson, who had not commented on the two other drop-outs, weighed in after Godlewski left the race.

"Showing their lack of respect for voters and the democratic process, the power brokers of the Democrat party have now cleared the field for their most radical left candidate," Johnson tweeted. "Socialist policies have produced this mess, & a radical left Senator from Wisconsin is not the solution."

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Barnes, 35, would become the first Black senator from Wisconsin if elected. He served two terms in the state Legislature before being elected lieutenant governor in 2018. Barnes opted against seeking a second term with Democratic Gov. Tony Evers to instead run for Senate.

Mandela Barnes

Mandela Barnes is the clearcut favorite to win the Democratic nomination for Wisconsin Senate after Sarah Godlewski dropped out of the race. (Photo by Handout/DNCC via Getty Images)

Godlewski’s decision to leave the race came after Outagamie County Executive Tom Nelson dropped out Monday and Barnes’ top rival, Alex Lasry, followed suit Wednesday. Godlewski and Nelson had been trailing Barnes and Lasry by double digits in public polling.

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"It’s clear that if we want to finally send Ron Johnson packing, we must all get behind Mandela Barnes and fight together," Godlewski said.

Several lower-tier candidates who were polling in the low single digits remain in the Aug. 9 primary, and even those who dropped out will still be on the ballot. In-person absentee voting began this week.

Barnes has emphasized his middle class upbringing as the son of a public school teacher and factory worker, both union members. Barnes paid no income tax and was on the state’s Medicaid program while running for lieutenant governor in 2018.

He has secured some big-name liberal endorsements in the primary, including Vermont Sen. Bernie Sanders, Massachusetts Sen. Elizabeth Warren and U.S. Rep. Alexandria Ocasio-Cortez.

Godlewski, the only woman in the race, had made fighting for abortion rights the center of her campaign. But she said she was ending her candidacy and backing Barnes because it would help the overriding goal of knocking off Johnson, a two-term incumbent and close ally of Trump.

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Barnes, who was scheduled to appear with Godlewski later Friday, said her decision put Democrats in a stronger position to defeat Johnson in November.

"This week has demonstrated what it looks like when we come together for a goal that is greater than ourselves," Barnes said in a statement. "We are building a coalition that crosses generations, crosses racial divides and political divides. A coalition that includes farmers, union leaders, teachers, small business owners, and working people all across this state."