NEW YORK - Former New York City Mayor Rudolph Giuliani began a fundraising tour Monday for Republicans locked in tight congressional races, a trip that is taking him into two presidential battleground states and heightening speculation about a possible White House run.

Giuliani, who has topped several national 2008 presidential polls in recent months, was to headline a cocktail reception in Cleveland on Monday night for two-term Sen. Mike DeWine. DeWine faces a stiff re-election challenge from Democratic Rep. Sherrod Brown.

Giuliani touches down in three states Tuesday, attending events for Arkansas gubernatorial candidate Asa Hutchinson, Illinois gubernatorial hopeful Judy Baer Topinka, and Pennsylvania Sen. Rick Santorum.

He'll also take in the All-Star baseball game in Pittsburgh on Tuesday night.

He completes the tour Wednesday with a breakfast fundraiser for Pennsylvania gubernatorial candidate Lynn Swann and a reception in Baltimore for Maryland Gov. Robert Ehrlich.

Of all the appearances, the Santorum fundraiser is perhaps the most significant, although Arkansas is intriguing because it is the former stomping ground of another potential presidential hopeful, Democratic Sen. Hillary Rodham Clinton.

Santorum, who polls show is running behind Democrat Bob Casey, is a firebrand conservative whose views on social issues like abortion strongly contrast with Giuliani's.

But Giuliani has been a dedicated ally, stressing Santorum's commitment to national security affairs at a fundraiser for the candidate in mid-April.

Giuliani, who has ridden a wave of national goodwill since his fabled performance in the wake of the Sept. 11, 2001 terrorist attacks, has been a proven draw at Republican fundraisers across the country.

He also hosted a major event in New York last month for his own political action committee, Solutions America, which pulled in about $2 million for GOP candidates.

All of this, however, begs the lingering question of Giuliani's own political plans.

When asked about his presidential prospects, Giuliani continues to insist he'll make a decision after the fall midterm elections.

But his travel schedule into presidential battlegrounds like Pennsylvania and Ohio - not to mention subtler clues, like a beefed-up Web site replete with news articles touting his popularity as a possible 2008 contender - suggest he is keeping the possibility very much alive.

“I don't understand people dismissing him. It doesn't make sense,” said Frank Luntz, a Republican pollster who has worked for Giuliani. “A leader in crisis defines a presidency. What the public saw and experienced in him on 9/11 set him apart from everybody.”

Indeed, the prospect of a Giuliani candidacy piqued the interest of political blogs again this weekend, when the veteran political columnist Robert Novak proclaimed that “well-connected public figures” say Giuliani has told them he “intends” to run in 2008.

Novak also reported that the same insiders warn that Giuliani's support for abortion rights, gay rights and gun control would disqualify him among the conservative voters who vote in GOP primaries.

Giuliani spokeswoman Sunny Mindel cautioned against reading too much into anything in the column, calling its sourcing “pretty vague.”

Still, the concerns raised in the piece largely reflected what many observers have long said: that Giuliani's strong showing in national polls belie some continued, underlying weaknesses to a potential candidacy.

Besides his position on social issues, conservative voters may question Giuliani's complicated marital history.

He married his third wife, Judith Nathan, after publicly acknowledging her as his mistress during his waning years as mayor.

He was ordered to pay $6.8 million to second wife Donna Hanover as part of a bitter divorce settlement.

Then there is Giuliani's close relationship with former New York City Police Commissioner Bernard Kerik, who flamed out as President Bush's choice to head the Department of Homeland Security under a cloud of ethical questions.

Kerik pleaded guilty recently to misdemeanor charges of accepting bribes as the city's corrections chief from contractors allegedly tied to organized crime.

But Quinipiac University polling director Maurice Carroll said that because of his 9/11 notoriety, Giuliani will always be evaluated by a different set of rules than other candidates.

“Rudy Giuliani on 9/11 became America's mayor and he's never going to lose it,” Carroll said.

“Kerik could become a serial killer, and it wouldn't matter. Giuliani may lose elections at some point, but he'll never lose that identity.”

As for his current fundraising trip - which includes presidential battlegrounds as well as a stop in Arkansas - Mindel said the choice of stops reflected a number of considerations.

“Geography, logistics, who needs help, where they need help and when,” Mindel said. “The typical things that come into political planning.”