WASHINGTON - Three years after the collapse of President Bush's plan for private Social Security accounts, Republican presidential contenders are eager to try again. Not so the Democrats, who gravitate toward increasing payroll taxes on upper-income earners to fix the program's finances.

With the notable exception of former Sen. Fred Thompson, a Republican, presidential hopefuls in both parties shy away from suggestions that might offend their own primary voters. As a result, bipartisan commissions to resolve the program's long-term financial problems are in. And longer waits for retirement are most definitely out.

Thompson's proposal, by contrast, includes lower-than-promised benefits for future retirees, as well as new private accounts to make Social Security solvent for 75 years. "If somebody's got a better idea let them put it on the table," he said recently, daring his rivals.

Given the divide between the parties, Social Security seems likely to become more of an issue during the 2008 general election than it has been in the campaigns for the presidential nominations.

For now, the most favored suggestion, creation of a bipartisan commission, seems to hold different meanings for different candidates.

Former New York Mayor Rudy Giuliani, a Republican, said earlier this fall he favors creation of a commission like the one that hatched a financial fix for the system nearly a quarter century ago. Yet, maneuvering for the support of the conservative Club for Growth, he also said, "I would rule out a tax increase," thus rejecting a key element of the 1983 compromise signed by then-President Reagan.

Sens. Hillary Rodham Clinton of New York and Barack Obama of Illinois are among the Democrats who favor a bipartisan commission. At the same time, they evidently seek to preserve their own maneuvering room.

"I'd take everything off the table until we move toward fiscal responsibility and before we have a bipartisan process," Clinton said in one recent debate, drawing criticism from fellow Democrats who accused her of ducking the issue.

"Everything should be on the table," Obama said over the summer. Now, in a shift in emphasis that has drawn notice by his rivals, he says, "We don't need to cut benefits or raise the retirement age," a position that flatly rules out neither approach.

In cases where Social Security has flared in the campaign, it's served as a stand-in for a broader debate over candidate candor.

"I think the American people ... deserve a president of the United States that they know will tell them the truth, and won't say one thing one time and something different at a different time," former Sen. John Edwards said at a debate on Oct. 30.

That was a barb aimed at Clinton, who had declined to state a position on higher taxes in an earlier debate, then told an Iowa voter she would consider them.

Under most recent estimates, the Social Security trust funds will begin paying out more money in benefits than they take in from payroll taxes beginning in 2017. By 2041, the funds would run dry, and under current law, an automatic cut in benefits would follow.

Flush from his re-election in 2005, Bush urged Congress to reduce promised benefits for future upper-income retirees. In addition, he called for creation of private accounts, funded with a portion of workers' payroll taxes. He said the result would be a financially solvent program and a chance at a more comfortable retirement for millions of Americans.

Democrats vociferously objected to what they called privatizing the New Deal-era program. Republicans eventually blinked in the face of public opposition. The plan never came to a vote.

"I would be totally opposed to the privatization of Social Security. That is a very bad idea and I am glad we rejected it," Democratic Sen. Chris Dodd of Connecticut said during a campaign debate this fall, a position shared by fellow Democrats.

Instead, several Democrats talk favorably about raising payroll taxes for upper-income wage earners. Under current law, the 6.2 percent Social Security tax is levied against a worker's first $97,500 in income, a level that rises annually with inflation.

Edwards, Dodd and Obama were among those who agreed in one recent debate they would allow income between $97,500 and about $200,000 to remain untaxed. They said the tax should be restored for money earned above that level.

"I do believe that people who make $50, $75, $100 million a year ought to be paying Social Security taxes on that income," said Edwards.

Among Republicans, higher taxes is a non-starter.

"It's the wrong way to go," former Massachusetts Gov. Mitt Romney said last month.

"The first thing we have to do is get a consensus behind private accounts if we're going to change it," Giuliani said in one debate. On that, he gets no disagreement from fellow Republicans.

"The president had the right idea, but he used the wrong word. When he used the word 'privatization,' it scared the daylights out of a lot of people," said Mike Huckabee, a Republican. In addition, the former Arkansas governor favors higher benefits for seniors who delay retirement past 70. He also advocates giving retirees an option of declining their benefits, and instead have Social Security issue a lump sum payment at their death, with the money going to their children or grandchildren.