MADISON, Wis. (AP) — Republican U.S. Sen. Ron Johnson of Wisconsin, one of former President Donald Trump’s most vocal supporters, said Sunday that he will seek reelection, avoiding a wide open GOP primary in the narrowly divided swing state.

Johnson had pledged in 2016 not to run for a third time, but he rescinded that promise and kicked around running again for months, saying circumstances have changed now that Democrats are in full control.

Johnson, 66, has long said his preference was to retire after two terms.

Even with Johnson in the race, razor-thin 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 narrow 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 mid-term 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 again in 2016. Johnson has long been aligned with Trump’s hardline policies and politics. He led the push to investigate Biden’s son Hunter and rarely broke with the 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 U.S. 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 and the state’s two largest newspapers in Milwaukee and Madison called for him to resign.

Johnson was also 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.

Many potential Republican candidates have been waiting on Johnson before deciding whether to run. Former U.S. Rep. Sean Duffy announced last week (Jan. 6, 2022) 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.