Republicans struggled to sort out Social Security (search) disputes among themselves Thursday as Democrats bought radio ads to attack President Bush and GOP allies in Congress along the next leg of his road trip pitching his overhaul.

At the Capitol, Senate Majority Leader Bill Frist (search) said Congress must confront Social Security's problems this year, dialing back his comments of two days earlier that action might have to wait — a turnabout Democrats wasted little time in mocking.

"We need to do it this year. Not the next year," Frist said Thursday on the Senate floor. "We are working toward this goal."

On Tuesday, Frist noted Democratic opposition and suggested action might have to wait. "I want to be realistic," Frist said then.

Bush wants action this year, though no piece of legislation has emerged as a leading contender and Bush has not laid out a comprehensive plan of his own. While supporters say the issue needs bipartisan support to pass, congressional Democrats are nearly unanimous in their opposition.

Republicans, too, have expressed skepticism about the Bush plan, and polls have found public support falling.

Bush proposes allowing younger workers to divert a portion of their payroll taxes into personal accounts that could be invested in stocks and bonds. In return, they would forgo some of the traditional Social Security benefit.

Other tax increases or benefit cuts would be needed to bring the system into solvency, though Bush has not embraced any of them. People 55 and up would see no changes.

On Wednesday, Senate Finance Committee Chairman Charles Grassley (search), who will shepherd any legislation, suggested that the controversy around private accounts was giving Democrats an excuse to ignore the program's serious financial problems.

"Maybe we ought to ... bring people to the table just over what do you do for the solvency," said Grassley, R-Iowa.

It's all left opponents feeling optimistic about how the debate is shaping up, a month after Bush laid out his ideas in his State of the Union address.

"The American people now understand that private accounts have nothing to do with the solvency of Social Security," said House Minority Leader Nancy Pelosi, D-Calif.

Senate Minority Leader Harry Reid, D-Nev., collected signatures of 42 Democratic senators on a letter to Bush asking about Treasury Secretary John Snow's comments this week that personal accounts did not necessarily have to be funded with Social Security tax dollars. Reid asked Bush to say if he would, in fact, be willing to jettison the centerpiece of his Social Security plan.

If Bush dropped his personal account proposal, the letter says, that "would eliminate a serious obstacle to the kind of bipartisan process that Democrats are seeking."

Appearing on CNN's "Inside Politics," Reid denounced Federal Reserve Chairman Alan Greenspan, who on Wednesday endorsed the private retirement accounts and pressed Congress to address the looming shortages in programs for the elderly.

"I'm not a big Greenspan fan. I voted against him the last two times," Reid said. "I think he's one of the biggest political hacks we have in Washington."

Other Democrats noted Frist's change in outlook, dubbing him a flip-flopper — a charge Republicans used repeatedly last year against Democratic presidential candidate John Kerry. "Profiles in flip-flopping," read a release from the Democratic Senatorial Campaign Committee. "Frist gets a taste of White House medicine."

Bush was heading out Friday to Westfield, N.J., and South Bend, Ind., the start of a 60-day, 60-stop blitz that the administration says will take top officials to 29 states.

The Democratic National Committee prepared to respond with radio advertisements in each market, targeting Reps. Chris Chocola, R-Ind., and Mike Ferguson, R-N.J., who have faced tough races in the past. The ads accuse Bush of wanting to "end Social Security's guaranteed benefits" and tie them to the "ups and downs of the stock market."

"Call Congressman Chocola and tell him to oppose President Bush's risky scheme," one ad says.

The ads, the first the DNC has produced on the issue, echo other spots by advocates who oppose Bush's ideas. At a rally ahead of the Bush visit to New Jersey, Americans United to Protect Social Security plans to launch a campaign spotlighting how people are helped by the program.

Bush said Thursday he was still in the early stages of selling his plan.

"I do believe we're making progress on the first stage of getting anything complicated and difficult done in Washington, and that is to explain the problem," he said.

The White House said Wednesday that its core message on Social Security will not change: The president will continue to discuss the program's financial problems and the value of personal accounts.

Many of the president's allies, though, suggest a change in message might be needed, and a debate was under way over whether Bush should lay out a more comprehensive plan of his own.

"The concern has been putting a plan forward would simply provide a target to attack," said Ed Lorenzen, executive director of Centrists.org, who supports private accounts. "There does seem to be a feeling you're not going to get Democrats to engage in the discussion until there's a plan from the president."

Michael Tanner of the Cato Institute and David John of the Heritage Foundation suggested a change in message, saying Bush should emphasize that personal accounts give individuals control over their own money.

Sen. Lindsey Graham, R-S.C., who has been trying to find a bipartisan deal, said the key is to focus not on the accounts, but on the importance of "repairing the safety net" to protect the most vulnerable seniors.

And Rep. Clay Shaw, R-Fla., said he was encouraged by Snow's comments suggesting administration flexibility on how the accounts might be paid for. Shaw's plan calls for funding private accounts with general revenue, not Social Security taxes.

"That gives it new life," Shaw said.