Scott Walker campaigns with Romney in Wisconsin

JANESVILLE, Wis.—Mitt Romney launched day four of his six-state battleground bus tour by sharing the stage with Wisconsin Gov. Scott Walker, who, earlier this month, survived a recall election against him over his decision to strip collective bargaining rights from state employees.

The two appeared together at a local textile company, which Romney visited as part of his tour to highlight the impact of President Barack Obama's economic policies on small-town America.

"We need a leader who believes in more freedom and more prosperity, a leader who believes in America," Walker told a crowd of several hundred people. "And that leader is Mitt Romney."

It was Romney's first joint appearance with Walker, whose fight against labor unions has made him a rock star within the conservative movement. While Romney often touted his relationship with Walker on the campaign trail during the state's GOP primary in April—including a phone call between the two just days before election day—the two never appeared together until now.

Walker told the audience he was "thankful" to still be the state's 45th governor and said he hoped that he would soon be negotiating with Romney as the "45th president." In response, Romney praised Walker's victory and suggested it would put him in a position to win the state this November.

"I think Obama had put this in his column," Romney told supporters. "But we're going to win Wisconsin."

Also on hand: Wisconsin Rep. Paul Ryan, who has been rumored to be on Romney's short list for vice president, and Republican National Committee Chairman Reince Priebus—both of whom cast dire forecasts for the country if Romney doesn't win this fall.

"Are you ready to save America and fire Barack Obama? We are in a battle for freedom in this country," Priebus declared, insisting "Obama's priorities are not America's priorities." He continued: "We need to end the nightmare that is in the White House. … He is more in love with the man in the mirror and the sound of his own voice than he is in following through on his promises to the American people."

[Get more updates from Romney's bus tour by following @hollybdc on Twitter]

It was Romney's first and only stop in Wisconsin, a state that some consider a must-win for him this fall. The Republican nominee now heads to Eastern Iowa, where he'll take a boat tour near Dubuque before heading to a rally in Davenport Monday night.