Democratic presidential nominee Kamala Harris and her newly selected vice presidential running mate, Minnesota Governor Tim Walz, campaigned for the first time together on Tuesday in Philadelphia, kicking off a multi-day tour of battleground states aimed at introducing Walz to the national stage.

In his remarks to a raucous crowd of more than 10,000 at Temple University, Walz described his upbringing in a small Nebraska town, his 24 years serving in the Army National Guard and his prior career as a high school social studies teacher and football coach.

"It was my students who encouraged me to run for office," he said. "They saw in me what I was hoping to instill in them: a commitment of common good, a belief that one person can make a difference."

He also went after the Republican presidential nominee, Donald Trump, and his running mate, Senator JD Vance, an early demonstration of how Walz will approach the traditional "attack dog" role of the vice presidential candidate despite his affable, folksy style.

"He mocks our laws, he sows chaos and division, and that's to say nothing of his record as president," Walz said of Trump. "He froze in the face of the COVID crisis, he drove our economy into the ground, and make no mistake, violent crime was up under Donald Trump. That's not even counting the crimes he committed."

Harris' entry into the race after President Joe Biden abandoned his reelection bid just over two weeks ago has rapidly upended the election campaign, with polls showing she has erased the lead Trump had built.

Walz criticized Republicans for pursuing restrictions on women's reproductive rights, an issue that has plagued Republicans since the U.S. Supreme Court in 2022 ended women's constitutional right to abortion.

"Even if we wouldn't make the same choice for ourselves, there's a golden rule: mind your own damn business!" he said, drawing a huge ovation.

Harris, speaking before Walz, listed his titles - husband, father, teacher, coach, veteran, congressman, governor - before predicting he would earn a new one in the Nov. 5 election: vice president of the United States.
"He's the kind of person who makes people feel like they belong and then inspires them to dream big," she said.

Harris, the U.S. vice president, announced her choice of Walz earlier in the day, opting for a vice presidential running mate with executive experience, military service and a track record of winning over the rural, white voters who have gravitated to Trump over the years.

The Harris campaign said it had raised more than $20 million after the announcement of Walz as the vice presidential pick.

Pennsylvania, the site of their first rally, is seen as perhaps the most critical state in what is expected to be a close election between the Democrats and their Republican rivals.