U.S. Sen. Arlen Specter yesterday called the early Republican presidential primary season a "succession of failures," citing flaws with his party's leading candidates and saying he hasn't decided who to support.

"I will tell people how I'm going to vote and take a stand when it's right," Mr. Specter, R-Pa., said during a meeting with the Pittsburgh Post-Gazette's editorial board. "It has to be one of these."

Mr. Specter, who himself briefly sought the Republican presidential nomination in 1996, spoke as voters were heading to the polls in Michigan's primary election.

He expressed his greatest disappointment with the candidacy of former New York City Mayor Rudy Giuliani, who led in national surveys throughout most of last year, but has fallen quickly after poor performances in the Iowa caucuses and the New Hampshire primary, where he barely competed.

"I thought he might help the Republican Party in Pennsylvania. I think he could have if he hadn't jumped around," Mr. Specter said, referring to Mr. Giuliani's move to the right on many issues, such as a promise to back conservative Supreme Court nominees.

Mr. Specter shares many of the moderate stances that Mr. Giuliani took as mayor -- both men support abortion rights -- and the Pennsylvania senator thought a Giuliani candidacy could win votes in the Philadelphia suburbs and among right-leaning Democrats in the state's southwestern corner.

He also said many anti-abortion Republicans throughout Pennsylvania had expressed tentative interest in Mr. Giuliani because they thought he could win if New York Sen. Hillary Rodham Clinton becomes the Democratic presidential nominee.

Mr. Giuliani could still emerge as his party's victor. He is campaigning heavily in Florida, which holds its primary Jan. 29.

Also, Mr. Specter said the Iowa Republican caucuses victory of former Arkansas Gov. Mike Huckabee may have helped Mr. Giuliani, by slowing down the candidacy of another strong rival, former Massachusetts Gov. Mitt Romney. "I don't know him," Mr. Specter said of Mr. Huckabee. "Let's see what more he has to say."

Arizona Sen. John McCain, who has surged in recent weeks, has problems with the party's conservative base, Mr. Specter said. He predicted that Mrs. Clinton would defeat Mr. McCain in the fall, because many voters are "tired of Republicans."

But the Pennsylvania senator said he thought that Mr. McCain could win if he faces the Democrats' Illinois Sen. Barack Obama. "He's a smart guy," Mr. Specter said of Mr. Obama, a one-term senator. "But in a long campaign, people are going to start to reflect about the 'red telephone' [the hotline that links the White House with the Kremlin in Russia] and how much experience he has."

Pennsylvania's primary election is April 22, giving the state less prominence in the early stages of the 2008 election season. Mr. Specter favors scrapping the current primary system and replacing it with alternating regional primaries.

"Pennsylvania is idiotic to let Iowa and New Hampshire exert so much influence," he said. "America is idiotic to let them have such influence on who is going to be commander-in- chief."