Even with Johnson in the race, Wisconsin is up for grabs with Senate majority control at play. President Joe Biden won the state by fewer than 21,000 votes after Trump’s similarly razor-thin victory in 2016.
Still, Republicans have reason to be optimistic about regaining control of the 50-50 Senate. The party that does not hold the White House generally gains seats in midterm congressional elections. Former President Barack Obama’s Democratic Party, for example, lost 63 seats in the House and six in the Senate in 2010.
Johnson rose out of the tea party movement in 2010, defeating Democratic U.S. Sen. Russ Feingold that year and in 2016. Johnson has long been aligned with Trump’s hard-line policies and politics. He led the push to investigate Biden’s son Hunter and rarely broke with Trump's White House.
Johnson emerged as one of Trump's loudest defenders in 2020, particularly after his election loss, and that support continued after the insurrection at the U.S. Capitol on Jan. 6, 2021. Johnson held a hearing where unfounded conspiracy theories about widespread fraud in the election were given a platform. He also espoused conspiracy theories related to the Capitol raid that attempted to shift blame for what happened away from Trump supporters.
Just before the Capitol was stormed a year ago, Johnson objected to counting the Electoral College votes from Arizona.
Trump endorsed Johnson in April and encouraged him to run.
Johnson's stance angered many conservatives in Wisconsin. The state's two largest newspapers in Milwaukee and Madison called for him to resign.
Johnson has been a loud voice for unproven COVID-19 treatments, and he accused the medical establishment and health agencies of failing to explore and promote the use of relatively inexpensive drugs previously approved for other uses as early interventions against the coronavirus.
Democrats running include Lt. Gov. Mandela Barnes; Milwaukee Bucks executive Alex Lasry; state Treasurer Sarah Godlewski; Outagamie County Executive Tom Nelson; and Steven Olikara, founder and chief executive of the nonprofit Millennial Action Project.
“Wisconsin voters will relish the opportunity to fire Ron Johnson, who has used his senatorial power to enrich himself and his wealthiest donors at the expense of the middle class," said Wisconsin Democratic Party Chairman Ben Wikler.
Many potential Republican candidates have been waiting on Johnson before deciding whether to run. Former U.S. Rep. Sean Duffy announced this week that he was not running for Senate or governor. Former Marine Kevin Nicholson, who lost a Republican primary for Senate in 2018, has said he would run for governor if Johnson seeks reelection.