Vice President Kamala Harris picked Minnesota Gov. Tim Walz to be her running mate on Tuesday, choosing an affable longtime politician who Democrats hope can keep newfound party unity alive in a campaign barreling toward Election Day.

Harris said in a post on social media that Walz has “delivered for working families” as a governor, coach, teacher and veteran. Walz called it “the honor of a lifetime” to be Harris’ vice presidential pick. The two will appear together in Philadelphia at an evening rally.

In choosing the 60-year-old 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.

He is joining Harris during one of the most turbulent periods in modern American politics, promising an unpredictable campaign ahead. Republicans have rallied around former President Donald Trump after his attempted assassination in July. Just weeks later, President Joe Biden ended his reelection campaign, forcing Harris to unify Democrats and consider potential running mates over a breakneck two-week stretch.

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 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.

Harris, second gentleman Doug Emhoff and Walz are set to appear together for an evening rally in Philadelphia, recalling a joint 2020 appearance by Biden and Harris in Wilmington, Delaware.

After Tuesday’s trip to Pennsylvania, they will spend the next five days flying thousands of miles around the country touring critical battleground states. They’ll visit Eau Claire, Wisconsin, and Detroit on Wednesday and Phoenix and Las Vegas later in the week.

Planned stops in Savannah, Georgia, and Raleigh-Durham, North Carolina, were postponed because of Tropical Storm Debby ’s effects.

A team of lawyers and political operatives led by former Attorney General Eric Holder pored over documents and conducted interviews with potential selections, and Harris herself met with her three finalists on Sunday. She mulled the decision over on Monday with top aides at the vice president’s residence in Washington and finalized it Tuesday morning, the people said.

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 proved himself as a champion for Democratic causes.

“It’s no surprise that San Francisco Liberal Kamala Harris wants West Coast wannabe Tim Walz as her running-mate – Walz has spent his governorship trying to reshape Minnesota in the image of the Golden State,” said Karoline Leavitt, Trump’s campaign press secretary. “Walz is obsessed with spreading California’s dangerously liberal agenda far and wide.”

Walz has been a strong public advocate for Harris in her campaign against Trump and Sen. JD Vance of Ohio, labeling the Republicans “just weird” in an interview last month. Democrats have seized on the message and amplified it since then.

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. Minnesota has a history of divided government, though, and the arrangement was surprisingly productive in his first year. But the COVID-19 pandemic hit Minnesota early in his second year, and bipartisan cooperation soon frayed.

Walz relied on emergency powers to lead the state’s response. Republicans chafed under restrictions that included lockdowns, closing schools and shuttering businesses. They retaliated by firing or forcing out some of his agency heads. But Minnesotans who were stuck at home also got to know Walz better through his frequent afternoon briefings in the early days of the crisis, which were broadcast and streamed statewide.

Walz won reelection in 2022 by nearly 8 points over his GOP challenger, Dr. Scott Jensen, a physician and vaccine skeptic. Democrats also kept control of the House and flipped the Senate to win the “trifecta” of full control of both chambers and the governor’s office for the first time in eight years. A big reason was the Supreme Court’s Dobbs decision, which held that the Constitution doesn’t include a right to abortion. That hurt Minnesota Republicans, especially among suburban women.

“Tim has been in the news because the country and the world is seeing the guy we love so much,” U.S. Sen. Amy Klobuchar said Monday.

Ken Martin, chair of the Minnesota-Democratic-Farmer-Labor Party said young people he spoke to on the campaign trail were “Walz pilled.”

Walz and other Democrats went into the 2023 legislative session with an ambitious agenda — and a whopping $17.6 billion budget surplus to help fund it. Their proudest accomplishments included sweeping protections for abortion rights that included the elimination of nearly all restrictions Republicans had enacted in prior years, including a 24-hour waiting period and parental consent requirements. They also enacted new protections for trans rights, making the state a refuge for families coming from out of state for treatment for trans children.

Their other major accomplishments included tax credits for families with children that were aimed at slashing childhood poverty, as well as universal free school breakfasts and lunches for all students, regardless of family income. They also enacted a paid family and medical leave program, legalized recreational marijuana for adults and made it easier to vote.