COLUMBIA, S.C. - Expected debate on Social Security in the Senate next year should give South Carolina's relatively green senators more exposure than newcomers usually warrant.

Sen. Lindsey Graham and Sen.-elect Jim DeMint, both Republicans, have worked on the issue for years and could have leading roles in the discussions about Social Security that President Bush made one of his second-term priorities last week.

"We'll reform our outdated tax code. We'll strengthen the Social Security for the next generation," Bush said as he laid out his agenda in a victory speech.

"What we're seeing now is the culmination of a lot of political capital that has been spent," DeMint said this week. Social Security "is no longer the third rail. People have touched it and lived."

He and Graham say action needs to come next year.

The next federal budget will have to include plans for up to $30 billion in Social Security subsidies, DeMint said. Congress now has to face decisions about cutting future benefits or raising contributions. "That's not something we can avoid any longer," DeMint said.

Bush and the Senate have little time to get major work done, Graham said.

"It's about momentum. ... You've got to strike while the iron is hot," he said. "Six months from now, people will be thinking about the 2006 Senate elections and the House elections" and support could fade.

The presidential push is good news for Graham and DeMint - and it's a bit of relief for South Carolinians, some of whom fretted the state would lose clout in Washington as the Senate delegation went from being one of the nation's grayest to its greenest.

Graham won his seat in 2002 as the nation's longest-serving senator, Strom Thurmond, retired. Last week, DeMint won the seat that longtime Sen. Ernest "Fritz" Hollings will retire from in January.

Historically, freshmen were seldom seen taking big roles in key Senate debates.

"These days in the Senate, seniority is helpful, but it is not everything like it used to be. What matters today in the Senate is if you can gain credibility on a policy issue," said Furman University political scientist Danielle Vinson.

With Social Security, "the fact that they've thought it through and can speak confidently on the subject certainly gives them clout," she said.

Graham and DeMint back plans to create personal savings accounts for younger workers while preserving the existing benefits of older workers and retirees.

Their plans aren't cheap; most agree the transition will cost at least $1 trillion.

Supporters say there is no other plan to deal with projected shortfalls as more baby boomers retire and the system begins paying out in benefits more than it collects in taxes in 2018.

Graham, who gained national recognition as a House prosecutor during President Clinton's impeachment, has introduced a bill that follows a recommendation of Bush's Social Security overhaul commission. It would let workers divert 4 percent of their payroll taxes into savings accounts and spreads transition costs over 10 to 15 years.

The transition costs could be handled by closing tax loopholes, decreasing pork barrel spending, borrowing money or increasing the cap on payroll taxes, Graham says.

He and DeMint know the political pressure that accompanies Social Security changes. Graham's overhaul plans in the House became a constant source of criticism in his Senate campaign two years ago.

DeMint's proposals also were criticized in this year's campaign but not nearly as much as his plans to overhaul the federal tax code. DeMint co-sponsored a House bill to implement a 23-cent national sales tax and end income and other taxes.

In a congratulatory call last week, Bush, who has rejected national sales tax concepts, encouraged DeMint to maintain his push for Social Security and tax reform.

"We talked about those two things. He said, 'Now is the time to get it done,'" DeMint said.

Graham likely will take a more visible role in the Social Security fight than DeMint, said Clemson University political scientist Dave Woodard. DeMint is "not a show horse, he's a workhorse," Woodard said.