(CNN) -- Sen. John McCain on Monday is campaigning through Pennsylvania with former governor and vice presidential contender Tom Ridge. John McCain's campaign is trying to portray the senator as a maverick who is willing to reach across the aisle. Ridge, the first-ever homeland security secretary, grew up in Erie and begin his political career in the northwest Pennsylvania city where McCain's two-day trip begins. McCain kicks off his day with a tour of a General Electric Co. plant, followed by a town hall meeting with workers. Pennsylvania is a key battleground state. According to CNN's electoral map, its voters are leaning toward Sen. Barack Obama. But some Pennsylvania Democrats say the only way Obama can take the state is by picking former rival Hillary Clinton as his running mate. Much of that sentiment comes from Clinton supporters who have yet to give up their dream of a joint ticket. Clinton won the state's primary in April. The state's governor, Ed Rendell, is still making the case that she should be Obama's No. 2. "I don't know any other talked-about contender who would have an impact in anything more than one state. Sen. Clinton would have an impact in 10 or 15 states and could make the difference in those states," he said. Obama's campaign said Sunday that when Obama does pick his running mate, the announcement will come via text message and e-mail to any supporters who sign up to receive the alert. The campaign said a message will be sent out "the moment Barack makes his decision." The Democratic contender is vacationing in Hawaii this week. He doesn't have any public events scheduled, but so far, he's made appearances on both days of his vacation. Meanwhile, Obama's campaign on Monday released a new ad that tries to paint McCain as a Washington insider with ties to lobbyists. The ad starts by saying that "for decades, he's been Washington's biggest celebrity. And as Washington embraced him, John McCain hugged right back." The ad, called "Embrace," flashes multiple images of McCain hugging President Bush, as well as clips from McCain's appearances on "The View" and late-night talk shows. The spot concludes by saying that McCain is "a Washington celebrity playing the same old Washington games." McCain was first to use the "celebrity" label in a negative ad. He has made the charge a common theme in his attacks on Obama. McCain's campaign has been trying to show that the senator has crossover appeal as a "maverick." The campaign will probably tout an endorsement coming from a New Jersey Democrat to help them make that case. Richard Gerbounka, mayor of Linden, is expected to announce his support of the Arizona senator Monday afternoon, according to two Republican sources. Gerbounka was first elected in 2006 as an independent. He later became a Democrat, and is now reaching across the aisle to back McCain as the senator ramps up efforts to appeal to independent voters. New Jersey is one of several battleground states that McCain and Obama are both pushing hard to win. An average of recent polls shows the Democrat is up by about 10 points in the state.