Their message included an economic agenda drafted a year ago to appeal to women, calling for pay equity, a higher minimum wage, affordable child care and paid leave for workers with sick children. The bus traversed the Democratic states of New York, Massachusetts and Illinois, as well as the party’s urban strongholds in the swing state of Ohio. Audiences largely came from local unions and party activists.

“If you want to grow the U.S. economy, the best thing you can do is engage women in the economic growth of our country,” Ms. Pelosi told some 150 people in Columbus, Ohio, on Tuesday. To the significant minority of men in the audience, she added, “Thank you for being our partners.”

The group engaged not only local television stations and newspapers, but also social media. With help from younger aides on the bus, they posted on Twitter with the hashtag “womensucceed” (and retweeted supportive comments, like from the singer-songwriters John Legend and Carole King); answered questions on Facebook; and recorded brief video messages, and dance moves, for the mobile app Vine. They created a website to promote their economic agenda and the stories of working women, who shared stages and talked about their struggles in each city.

“Our whole goal is: If people know about this, more people will vote,” Ms. Pelosi said in an interview as the bus sped through Republican-leaning Indiana. “If more people are voting — particularly these women who need this the most, single moms — then Democrats and Republicans will pay more attention.”

“Whatever happens to you in the election,” she added, hinting at the challenge for Democrats in November, “you’ve got to advance the cause. And that cause is for opportunity for women.”

The partylike atmosphere belied the Democrats’ political problems, as well as the bus’s depressingly dark décor. (While its exterior was wrapped in the purple, gold and white colors of the women’s suffrage movement — emblazoned with the words, “When Women Succeed, America Succeeds: Women on a Roll” — the interior was more masculine: browns and faux leather.)

A refrigerator was stocked with water, sodas and ice cream, and Ms. Pelosi ate whole pints of chocolate ice cream, including for breakfast. There was no beer or wine, even when the women monitored several primary election returns on their laptops and cellphones past midnight on Tuesday en route to Chicago.