Vice-President Kamala Harris picked Minnesota governor Tim Walz to be her running mate on Tuesday, according to three people who spoke to The Associated Press on condition of anonymity.

In choosing Walz, she is turning to a Midwestern governor, military veteran and union supporter who helped enact an ambitious Democratic agenda for his state, including sweeping protections for abortion rights and generous aid to families.

Harris hopes to shore up her campaign’s standing across the upper Midwest, a critical region in presidential politics that often serves as a buffer for Democrats seeking the White House. The party remains haunted by Republican Donald Trump’s wins in Michigan and Wisconsin in 2016. Trump lost those states in 2020 but has zeroed in on them as he aims to return to the presidency this year and is expanding his focus to Minnesota.

Walz, 60, is joining Harris during one of the most turbulent periods in modern American politics, promising an unpredictable campaign ahead. Republicans have rallied around Trump after his attempted assassination in July. Just weeks later, President Joe Biden ended his re-election campaign, forcing Harris to unify Democrats and consider potential running mates during an exceedingly compressed time frame.

The three people spoke on condition of anonymity to avoid pre-empting the official announcement.

Harris, the first Black woman and person of South Asian descent to lead a major party ticket, initially considered nearly a dozen candidates before zeroing in on a handful of serious contenders, all of whom were white men. In landing on Walz, she sided with a low-key partner who has proven himself as a champion for Democratic causes.

Walz has been a strong public advocate for Harris in her campaign against Trump and Vance, labelling the Republicans “just weird” in an interview last month.

During a fundraiser for Harris on Monday in Minneapolis, Walz said: “It wasn’t a slur to call these guys weird. It was an observation.”

Walz, who grew up in the small town of West Point, Nebraska, was a social studies teacher, football coach and union member at Mankato West High School in Minnesota before he got into politics.

He won the first of six terms in Congress in 2006 from a mostly rural southern Minnesota district, and used the office to champion veterans issues.

Walz served 24 years in the Army National Guard, rising to command sergeant major, one of the highest enlisted ranks in the military.

He ran for governor in 2018 on the theme of “One Minnesota” and won by more than 11 points. As governor, Walz had to find ways to work in his first term with a legislature that was split between a Democratic-controlled House and a Republican-led Senate.