Mayor Pete wants to be President Pete.

Pete Buttigieg, the mayor of South Bend, Ind., who has seen his poll numbers surge in recent weeks, officially declared on Sunday that he's running for president – in a speech where he highlighted both his progressive values and Midwestern upbringing.

"I ran for mayor in 2011 knowing that nothing like Studebaker would ever come back—but believing that we would, our city would, if we had the courage to reimagine our future," Buttigieg said in a speech inside South Bend's Studebaker auto plant. "And now, I can confidently say that South Bend is back."

He added: "There’s a long way for us to go. Life here is far from perfect. But, we’ve changed our trajectory, and shown a path forward for communities like ours."

MAYOR PETE BUTTIGIEG CALLS OUT BIG TECH'S 'MONOPOLY POWER'

The 37-year-old Afghanistan War veteran, who has been exploring a White House run since January, now joins the field of a dozen-plus rivals and one that is likely to reach 20 or more.

Over the past few months, Buttigieg has appeared frequently on national TV news and talk shows and developed a strong social media following with his message that the country needs "a new generation of leadership."

“[The future] calls for hopeful, audacious voices in our community,” Buttigieg said on Sunday. “And, yes, it calls for a new generation of leadership in this country.”

Buttigieg's poll numbers have climbed. Some polls put him behind only Vermont Sen. Bernie Sanders, who sought the party's nomination in 2016, and former Vice President Joe Biden, who has not yet said he's running.

Buttigieg's campaign raised more than $7 million in the first three months of this year, a total eclipsed by Sanders' leading $18 million but more than Sens. Elizabeth Warren of Massachusetts, Amy Klobuchar of Minnesota and Cory Booker of New Jersey, among others.

His challenge: finding a way to sustain the momentum over the long term and avoiding becoming a "flavor-of-the-month" candidate. Scrutiny of his leadership in South Bend has increased, as has his criticism of Vice President Mike Pence, who was Indiana's governor when Buttigieg was in his first term as mayor.

BUTTIGIEG CONTRASTS HIMSELF WITH BIDEN AND SANDERS

Buttigieg would be the first openly gay nominee of a major presidential party; he married his husband, Chasten, last year. He would be the first mayor to go directly to the White House. And, he would be the youngest person to become president, turning 39 the day before the next inauguration, on Jan. 20, 2021. Theodore Roosevelt was 42 when he took office, while John F. Kennedy was 43 and Bill Clinton 46.

Buttigieg argued that the best way for Democrats to defeat President Trump may be to nominate a mayor experienced in helping to revive a Midwestern city once described as "dying," rather than a politician who has spent years "marinating" in Washington.

He has criticized Trump's campaign slogan, "Make America Great Again," saying the way to move the country forward is not to look backward or cling to nostalgia or an old way of life.

“We have changed our trajectory,” Buttigieg said. “That’s why I’m here today to tell a different story than ‘Make America Great Again.”

He added: “There is no such thing as honest politics that includes the word 'again.'”

South Bend, which neighbors the University of Notre Dame, was hit hard by the decline of manufacturing, dating to the 1963 closing of the Studebaker auto plant that costs thousands of residents their jobs.

CLICK HERE TO GET THE FOX NEWS APP

The hulking, dilapidated factory loomed over the city for much of the past 60 years as what Buttigieg called a daily reminder of South Bend's city's past.

Buttigieg gave his speech inside that building, which underwent a multimillion-dollar renovation led by a private developer with help from state grants and tax increment financing from the city. The newly remodeled structure is now part of a mixed-use technology center outside the city's downtown.

The Associated Press contributed to this report.