The charismatic former pizza executive is throwing his weight behind a handful of Republican congressional hopefuls who are intent on advancing the conservative platform he espoused — including his signature “9-9-9” tax plan — campaigning for some of them and endorsing others.

Cain will hit the road this week for a four-stop tour with Michigan Senate candidate Pete Hoekstra and for a job creation-focused event with Samuel Wurzelbacher — better known as “Joe the Plumber” — who is waging a bid for a northern Ohio-based House seat.

Cain’s emergence on the congressional trail after abandoning his White House bid in December following numerous allegations of sexual improprieties is part of an effort to leave an indelible imprint on the 2012 election and to remain in the spotlight. It’s a role similar to the one former Alaska Gov. Sarah Palin embraced in 2010, when she sought to raise her profile by throwing her backing to conservative candidates she labeled “Mama Grizzlies.”

“My sense is that he really wants to continue his message. Despite the fact that he’s no longer in the presidential race, he really wants to continue talking about issues,” said Florida Republican Craig Miller, whose Senate candidacy Cain has endorsed. “He’s trying to influence the debate.”

“He’s endorsing candidates like myself, who are like-minded and who have a similar philosophy,” Miller said.

“When he left the presidential race, he left with a lot of people wanting him to stay in, and now I think he wants to help Republicans get elected,” said Martha Zoller, a conservative talk radio host who’s running for a Georgia congressional seat with Cain’s backing. “I’m happy to have Herman’s support. He brings with it grass-roots support that a candidacy like mine needs.”

Each of the candidates Cain is backing has embraced the former presidential contender’s 9-9-9 tax plan — his trademark and oft-repeated proposal — and has made reforming the nation’s Tax Code a cornerstone of their campaigns. Cain spokeswoman Kathy Hoekstra — who is not related to the Michigan Senate candidate — said Cain is actively seeking out candidates who would seek to enact the 9-9-9 plan if they are elected.

After leaving the presidential race, Cain embarked on the Cain Solutions Revolution, a bus tour aimed at rallying support for the 9-9-9 plan across the country.

Cain is touting the House and Senate candidates who support his tax plan on his website, Cain Connections. And when he appeared with Miller in Orlando recently, Cain was quick to point out that the Florida Republican had given the proposal his blessing.

“He recognized that the 9-9-9 plan resonated with the people of the United States, and he wanted a way to keep 9-9-9 alive,” said Kathy Hoekstra.

Cain is also rewarding longtime friends with his backing.

He has known Miller, who like Cain is a former restaurant executive, for more than 20 years. Zoller, for her part, credits herself with giving Cain his start in conservative radio. After his unsuccessful 2004 Georgia Senate bid, Cain filled in on her show. And when Cain kicked off his presidential bid last year, Zoller was on hand to emcee the event.

“Herman and I have been friends for years,” Zoller said. “Herman has always been a good friend.”

For Wurzelbacher, the Cain endorsement is something of a thank-you for the Ohio Republican’s support of his presidential candidacy. During his speech before the Conservative Political Action Conference this month, Cain praised Wurzelbacher for supporting his 9-9-9 plan and announced that he was formally endorsing Wurzelbacher’s bid.

Cain has proven to be an energetic surrogate. Last month, after stumping with Miller in Orlando, he cut a TV ad praising the Florida Republican as a political outsider who “gets it.” Cain has already held one standing-room only event for Zoller, cut a robocall for her and donated $2,000 to her campaign. He’s expected to return to Georgia for a fundraising event benefiting Zoller.

To Zoller, Cain brings to the campaign trail the same grass-roots enthusiasm that powered his presidential bid.

“He is very popular in northern Georgia. I meet people every day that say he shouldn’t have gotten out of the presidential race,” she said. “An endorsement from Herman brings with it people who want to volunteer and who want to give money.”

“It is an endorsement that is not just a name on a piece of paper,” she said.

Democrats, however, have tried to make hay out of Cain’s reappearance on the campaign trail.

The Democratic Senatorial Campaign Committee has lambasted Pete Hoekstra, who is challenging Democratic Sen. Debbie Stabenow, over the past month for his support for Cain’s 9-9-9 plan, sending out press releases accusing the Michigan Republican of advocating a policy it calls advantageous to the rich but damaging to the poor.

“The Cain train derailed months ago but Pete Hoekstra is still trying to get on,” Shripal Shah, a DSCC spokesman, said in an email.

But Hoekstra, who reached out to the Republican after he exited the presidential race, said Michigan voters should get ready for more of Cain.

“I expect we’ll have a good day on Thursday, and I expect we’ll see him much more often. This won’t be the only time he’ll be in Michigan,” Hoekstra said. “This will be the first of a number of trips.”