Bush and supporters of his plan have tailored their pitch to blacks, contending that they are most likely to benefit from the change. But lawmakers say blacks can't afford to support a plan that puts their guaranteed retirement benefits at risk.

Despite the prospects of sparring with the Republicans who control Congress and the White House, many members of the Congressional Black Caucus, a group of 43 Democrats, are preparing for the contentious political fight.

"It's a myth that African-Americans would fare better under privatization," said Rep. Stephanie Tubbs Jones (D-Ohio), a member of the caucus.

Bush has made the overhaul the centerpiece of his domestic agenda, outlining a plan that would allow younger workers to put a portion of their Social Security taxes into private investment accounts.

But caucus members, who raised the issue with Bush in a meeting last month, argue that blacks could be hurt by relying on a shaky stock market. They say blacks tend to earn less than whites, suffer higher rates of disability and are out of the work force longer in part because of discrimination.

Aside from retirement benefits, blacks rely heavily on the program for disability and survivor benefits.

Rep. Harold Ford Jr. (D-Tenn.), a caucus member, favors private investment accounts, but he said it's too risky to divert Social Security taxes.

"If people lose money, where else are people going to turn but to the federal government to help them out?" Ford said.

Supporters of investing in personal accounts say blacks, particularly men, tend to die sooner than whites and therefore don't collect as much in benefits under the current system.

Bush's plan would allow low-income blacks to collect more in benefits because of the higher rate of returns and build wealth that could be inherited, said Michael Tanner of the Cato Institute, a libertarian think tank.

"People understand there's a need to build wealth. People understand that black men die early and get a bad deal from Social Security," said Tanner, adding that inheritable wealth has appeal among some blacks.

Rep. Charles Rangel (D-Harlem) said he is offended that Bush has failed to address the claim that the system is unfair to blacks because they don't live as long.

"But instead of investing in health care or economic development in low-income areas, the Republicans throw up their hands and say, 'privatize Social Security,'" Rangel said.

Lawmakers on both sides of the issue are reaching out to blacks, said William Novelli, chief executive of AARP, a senior lobbying group that opposes private accounts. "If you are going to carry the day, you need to persuade African-Americans your way," he said.

Rep. Elijah Cummings (D-Md.), a former caucus chairman, acknowledged that Bush has the bully pulpit, but said it helps that some key Republicans have expressed concern.

"We've got our work cut out for us," Cummings said. "[But] I don't think we can sit on the sidelines. There are too many people depending on it."