Nearly seven months since his ticket lost the 2024 presidential election, Tim Walz is trying all at once to make amends for everything he thinks went wrong.

He is going to Republican areas where Democrats lost ground. He is sitting for countless interviews after former Vice President Kamala Harris’s campaign limited his media exposure. And as his party engages in collective finger-pointing, he is among the few Democrats admitting that they themselves made mistakes.

“I know my job and I didn’t get it done,” Mr. Walz, the governor of Minnesota, said last week on a podcast hosted by former Senator Jon Tester, the Montana Democrat.

The Tim Walz atonement-and-explanation tour had its biggest audiences to date on Saturday, when he delivered speeches to Democratic Party conventions in South Carolina and California.

“This dude’s the last guy I want to tell us about ‘we lost our way.’ You’re the guy who lost,” Mr. Walz said to the crowd in Columbia, S.C., on Saturday morning, imagining what listeners might be thinking. But, he added, “none of us can afford to shy away right now from asking the hard questions and doing the things we need to do to fix it so that we win elections.”

His approach stands in stark contrast with how his running mate has dealt with their loss. Ms. Harris gave a paid speech in Australia, appeared at the Met Gala in New York (though she skipped the red carpet) and spoke for barely more than 15 minutes to a political group in San Francisco. Even as she weighs a run for governor of California, it was Mr. Walz who was the main attraction at that state’s Democratic convention.