Republican Gov. Mitt Romney of Massachusetts raised cash for his campaign committee on Monday in what is shaping up as enemy territory — the home state of potential 2008 presidential rival John McCain of Arizona.

Romney held a fundraiser in Phoenix, a foray that Romney's staff says highlights his ability to compete in Southwestern and Mountain states. They are home not only to McCain and a coveted bloc of Republican-leaning voters, but also many of Romney's fellow Mormons.

It is McCain whom Romney singled out when the governor announced in December he would not seek a second term this year. Unlike the senator, who once joked he thought about being president "every day in the shower," Romney said his interest was more like the movie "Star Wars:" "It's in a galaxy far, far away."

In repeated interviews, Romney has questioned the effectiveness of the 2002 McCain-Feingold campaign finance law, arguing it has had "unintended consequences" and "driven money into secret corners."

Romney's staff regularly quips about McCain's age and questions the senator's ability to win over the influential and monied supporters of President Bush after their own rivalry developed during the 2000 presidential race.

By 2009, McCain would be 72, three years older than Ronald Reagan was in 1981 when he became the oldest first-term president.

McCain's staff, speaking privately like Romney's to avoid incurring the boss' wrath, labels Romney a johnny-come-lately to conservative Republican and national security causes. They also question whether a dashing candidate dubbed "Matinee Mitt" has the mettle to endure a rough nominating battle.

McCain himself is far more generous.

"I think he's a very good man; I think he's extremely attractive," the senator said in a recent interview in Washington. "I had some dealings with him when he was in charge of the Olympics, cleaning up the Olympics, where he did a great job."

As for Romney's criticism of his campaign finance bill, McCain said: "It's no longer possible for a trial lawyer or a union leader or a corporate head to be called by a senator who's a powerful committee chairman and say, 'I want a check for six figures and by the way, your legislation is up before my committee."'

While the general election is still more than 2 1/2 years away, the fact that there will be neither a sitting president nor vice president running for the White House in 2008 has touched off early and intense competition in both parties.

Public opinion polls have placed McCain atop the GOP pack. But Romney has not avoid the sniping.

During a recent visit to the Olympics in Italy, former New York City Mayor Rudolph Giuliani — who is also considering a 2008 bid — said the security in Turin "is even an improvement" over the tight security at the Salt Lake City games in 2002.

Left unsaid was that Romney had run those Olympics in Utah.

"Romney's comments have not gone unnoticed, and his visit to Phoenix to raise some money has raised some eyebrows," said Scott Reed, a Republican political consultant who was campaign manager for Bob Dole's 1996 presidential campaign.

"I'm not sure it's a smart long-term strategy," Reed added. "One thing I've learned about this business is that candidates remember — especially early on in campaigns when people are just getting started."

A Romney spokeswoman insisted that any talk of a McCain-Romney rivalry was both premature and off target.

"Governor Romney has a great deal of respect for Senator McCain and considers him a true American hero," said Julie Teer, political director of his Commonwealth PAC. "The purpose of the governor's trip to Arizona is to raise money for the Commonwealth PAC to help Republican candidates up and down the ticket there in 2006."