The lieutenant governor of Wisconsin, Mandela Barnes, will attempt to become the first African American from the state to serve in the US Senate.

Barnes said on Tuesday he would join a crowded Democratic field for the seat currently held by the Republican Ron Johnson, a prominent rightwinger and ally of Donald Trump.

Barnes, 34, is the first Black lieutenant governor in Wisconsin history. Giving up a chance to run for a second term in 2022 with Governor Tony Evers, he has become the seventh Democrat to enter the Senate race with an eighth expected soon.

Barnes released a campaign video ahead of an event in Milwaukee, his home town.

“I’m running for the United States Senate because when things get tough, we shouldn’t lower our expectations,” he said. “Instead of changing our dreams, we need to change the game. Hard-working Wisconsin families deserve every opportunity, but politicians like Senator Ron Johnson aren’t delivering.”

Johnson has not said if he will seek a third term, but by June he had raised more money than any Democrat. His spokeswoman did not immediately comment.

Barnes brings some name recognition to a Democratic field that includes office holders, political newcomers, a doctor and an executive with the Milwaukee Bucks NBA franchise.

Barnes, who says the party must do a better job connecting with young people and people of color, played up his middle-class upbringing.

“My father worked on an assembly line for 30 years, my mother taught in Milwaukee public schools,“ Barnes said. “They were able to provide me with a foundation for opportunity. I believe we need to build a better America where the opportunity I found isn’t so rare.”

Barnes won the primary for lieutenant governor in a blowout in 2018 before Evers defeated Scott Walker. Former lieutenant governor Rebecca Kleefisch is expected to run against Evers next year. Barnes was outspoken in the campaign, accusing Walker of ignoring “people who look like me” and saying Trump wanted to create “a superior race”.

Barnes also was outspoken following the police shooting in Kenosha last summer of Jacob Blake, a Black man. Barnes criticized Trump for visiting amid protests and was critical of how police reacted to Kyle Rittenhouse, a white teenager who shot and killed two protesters.

Evers tapped Barnes to lead a taskforce on the climate crisis that made 55 recommendations. Barnes has advocated for tighter gun control and redistricting reform.

Barnes received his college diploma from Alabama A&M in May 2020, 12 years after he attended classes and two years after he said he had a degree when he had not fulfilled all the requirements to get one.

Barnes was in the state assembly from 2013 to 2017. Rather than seek a third term he ran for the state senate against a Democratic incumbent, Lena Taylor, and lost.

On Tuesday, Evers said Democrats were lucky to have strong candidates to take on Johnson and “send him packing”.