At a Republican retreat at the Greenbrier resort in the West Virginia mountains, Bush tried to convince members that establishing private retirement accounts is the way forward for Social Security despite the political risks and transition costs estimated at up to $2 trillion.

"He told us he's going to help us by providing some cover on some of the most important and politically difficult issues," said Rep. Rob Portman, an Ohio Republican.

House Budget Committee Chairman Jim Nussle agreed, adding that Bush's generally aggressive and upbeat tone also helped to energize some members who are facing a difficult re-election fight next year.

"That enthusiasm, that attitude is very helpful to members who live in any amount of uncertainty of how to proceed," Nussle said.

But Nussle, an Iowa Republican, and others acknowledged that Bush and party leaders in Congress still have more work to do to make his case for restructuring Social Security. "Does he have more selling and educating to do? Of course," Nussle said.

Overhauling Social Security, the legal system and immigration laws will be major elements of Bush's State of the Union speech on Wednesday night, an address expected to offer more details on his second-term plans than his lofty Jan. 20 inaugural address.

"I look forward to talking to the country about the need to address big reforms like Social Security," Bush said in brief public remarks to the Republican gathering before answering members' questions in private.

Freshman Sen. John Thune, a South Dakota Republican, noted prior to Bush's speech that Republicans face an uphill battle in combating Democratic accusations that Bush's plan will undermine the solvency of Social Security program.

"I think we've gotten a little behind the eight ball," said Thune.

Bush wants to restructure Social Security this year before attention turns to the 2006 mid-term elections. Democrats have already signaled they will fight private accounts as a danger to Social Security and argue that the 70-year-old retirement system is not in crisis.

Many Republicans fear changing Social Security will cost them dearly at the polls if retirees blame the administration for cutting their old-age pensions.

Congressional Republicans have held annual retreats every year since Bush took office in 2001. While they have expanded their majorities in Congress since then, they have also appeared this year to increase their differences with the president.