President Bush (search) was back on the Social Security stump Friday, taking his 60-day campaign to reform the nation's retirement system to a gymnasium in Falls Church, Va.

He told the audience that it was urgent that Congress help him ensure Social Security's solvency, because their golden years could depend on it.

And he warned opponents not to "play politics as usual" with his proposals, adding that "those who block meaningful reform are going to be held to account in the polls.

"If you're a younger worker, and you start paying into the payroll system today, and 2041 is about the time you start retiring, I'm telling you, the system is going to be bankrupt unless we do something about it," the president said.

"In other words, you're working all your life, you're putting money in, and by the time it comes for you to get ready to retire, there's nothing there. That's a problem, folks, and it requires a solution, requires people to come together to make this work."

Bush's proposals are confronting stiff opposition from Democrats who fear his true agenda is to wean workers off government assistance in retirement, which they say could leave many at risk of falling into poverty.

Republican lawmakers, meanwhile, began working to ensure that the president has a plan on his desk by the summer.

"House Republicans are ready to roll up their sleeves and do some hard work on Social Security. We look forward to searching for solutions so that younger workers aren't left with an empty promise from the government," said Speaker Dennis Hastert, R-Ill.

Rep. Bill Thomas, R-Calif., chairman of the House Ways and Means Committee, said he intended to hold weekly hearings beginning in May until he is ready to present legislation to the panel in June.

The president "delivered phase one," he said of Bush, who has campaigned extensively to build support for changes in the system.

"It is now our responsibility to follow through legislatively, and we will do it in as short a time as possible so we will get that done this year," Thomas said.

Finance Committee Chairman Charles Grassley (search), R-Iowa, has said he hopes to have legislation before the panel by the end of July.

But some lawmakers on the Ways and Means Committee issued a critical paper entitled "Sliding Scale Benefit Cuts." Democrats and their supporters said the president's plan did not do enough to protect the middle class.

House Minority Leader Nancy Pelosi indicated Democrats would not budge until private accounts were taken off the table.

"Democrats believe that slashing Social Security benefits to pay for privatization is the problem, while Republicans believe massive benefit cuts are the answer," the California Democrat said.

Some high-profile Republicans have also grown uncomfortable with the idea of private accounts. Earlier this week, Grassley indicated he may encourage the panel to approve a bill that doesn't include personal accounts in order to get it on the Senate floor.

Some Democrats said Bush's plan was part of a larger pattern of fiscal irresponsibility.

"The president offered a plan to cut Social Security benefits and increase the deficit by $4 billion," said Democratic strategist Mark Mellman.

Bush's supporters echoed his calls for Democrats either to come up with an alternative plan or to begin working with Republicans on a solution.

"The Democrats do not have a plan. The president does. And now it's time for both sides to come together and effect change for all Americans," said Brad Blakeman, former deputy assistant to the president.

But Mellman said Democrats were merely sticking up for their principles, not being obstructionist.

"The fact is, the American middle class does not need Social Security taken away from them. I think Democrats are happy to sit down with the president and talk about real solutions to shore up Social Security's viability, but we do not need to be cutting 70 percent of Americans' benefits," the former pollster for Sen. John Kerry said.

More Help for Poor, Less for Others

In a nationally televised prime-time news conference Thursday night, Bush did not step away from his proposal to have personal accounts in Social Security, as some had predicted, but he did add something new.

The president embraced progressive indexing (search), which would provide a faster rate of growth in benefits for lower-income workers than for those in higher brackets.

"I believe a reformed system should protect those who depend on Social Security the most. So I propose a Social Security system in the future where benefits for low-income workers will grow faster than benefits for people who are better off," Bush said Thursday night.

Progressive indexing calls for basing the benefits of low-income workers on average wage increases over their time in the workforce, while basing benefits for those earning more than $113,000 on average price increases over that time. Benefits for middle-income workers would be a hybrid of the two systems.

Since the wage index generally grows significantly faster than the price index, low-income workers would receive greater benefits than higher-income workers.

The plan is the brainchild of Robert Pozen (search), a Democratic Social Security expert and chairman of Boston-based MFS Investment Services. Pozen testified before the House Ways and Means Committee on Tuesday, and last week Bush called his proposal "a good idea."

Thursday night's news conference appeared to be the first time Bush had publicly endorsed progressive indexing.

Though the latest outline of Bush's Social Security plan (search) could anger conservative Republicans who oppose anything that smacks of entitlement, the new emphasis on income-based distribution sat well with some Democrats.

Elaine Kamarck, a former senior campaign adviser to Al Gore who lectures at Harvard's Kennedy School of Government, praised the president's approach to Social Security.

"The proposal that President Bush put on the table is, in fact, a very interesting and progressive way of looking at the solvency problem," Kamarck told FOX News.

Former Delaware Gov. Pete du Pont, a Republican, predicted that the middle-class would warm to Bush's proposals.

"The president did say he would raise the tax rate on higher-income people, but his theme was ownership and choice in ideas," said du Pont.

"I think the president will succeed in this effort because he is talking about things middle-class people want. I think after a little scuffling this will work," he said.

But Kamarck said that if Bush really wants to attack the issue of Social Security solvency, he will eventually have to abandon the idea of private accounts.

"If down the road the president backs away from privatization, as I suspect he will, then I think you'll begin to see outlines of a deal," Kamarck said.

The Associated Press contributed to this report.