As they contemplated the political landscape earlier this year, Texas Gov. George W. Bush and his advisers faced a quandary: How could he talk about curing poverty, healing the sick, caring for the needy and reforming criminals without running headlong into conservative skepticism about social welfare programs?

The answer, Bush says, is that people of religious faith, not government, are best equipped to change the world for the better.

The concept has become Bush's signature campaign issue, a topic he addresses in every speech. The most controversial component is his support for the expansion of "Charitable Choice," a barely noticed provision in the 1996 Welfare Reform Act that allows religious groups to compete for government contracts to provide welfare services.

New legislation by that provision's sponsor, Sen. John D. Ashcroft (R-Mo.), would extend Charitable Choice to every major area of federal social services, including drug treatment, homeless programs, senior programs, housing, juvenile services, substance abuse treatment and prevention, and sexual abstinence education.

While the proposed legislation would forbid the use of government funds to promote religion directly, it would allow federal funds to go to groups that proselytize, raising difficult questions about the separation of church and state.

Bush says he is not trying to shove religion down anyone's throat, but rather to foster an environment in which religion is available to those who seek it. He has been one of the most aggressive governors in instituting Charitable Choice programs, pushing the concept into state services such as the Inner Change prison program.

"This enables him to talk proactively on faith in a way that doesn't divide people," said Ralph Reed, a Bush adviser and former executive director of the Christian Coalition. "It has taken the underlying message of traditional values and allowed it to be presented in a nontraditional way that is caring and not judgmental."

Despite this appeal, the idea is politically explosive.

The Clinton administration has barred "pervasively sectarian" groups from receiving government contracts. Religious groups that operate primarily as secular service-providers, such as Catholic Charities, have been allowed to participate. But proselytizing religious groups, such as a gospel mission that runs a homeless shelter, have not.

Social conservatives contend that this is a deliberate effort to undermine Charitable Choice. "From day one, the administration has fought a determined, if unsuccessful, rearguard action against the law," said Ashcroft aide Steve Hilton.

Liberal advocacy groups, meanwhile, have been monitoring Charitable Choice programs, looking for potential legal challenges.

The constitutionality of programs that mingle elements of church and state is very much an open question. The Supreme Court has allowed religious groups to be involved in government programs, but it has barred the use of public funds to promote religious doctrine.

In May, Vice President Gore surprised both opponents and supporters of Charitable Choice by endorsing the concept in a speech in Atlanta.

"The men and women who work in faith- and values-based organizations are driven by their spiritual commitment," Gore said. "They have done what government can never do."

But there appear to be differences in how far Bush and Gore are ready to go in this direction. In his Atlanta speech, for example, Gore warned that "we must continue to prohibit direct proselytizing as part of any publicly funded efforts."

"For [Gore] to endorse Charitable Choice means he's endorsing very significant steps beyond what the Clinton administration has done, but certainly in a more restrictive sort of model [than Bush]," said Stanley Carlson-Thies, an official at the Center for Public Justice, a nonpartisan, religious think tank.

Bush believes that a religious group's message is fundamental to the delivery of services and that "a very important secondary goal is transforming lives through a belief in God and value systems," said Indianapolis Mayor Stephen Goldsmith, Bush's domestic policy adviser.

On his Web site, georgewbush.com, the Texas governor promises that in addition to expanding Charitable Choice, he would make "a concerted effort to identify and remove all barriers" to the use of federal funds by religious groups.

Yet many religious groups are uncomfortable with this idea. Just this week in Texas, 400 church leaders criticized Bush and Gore for supporting the expansion of Charitable Choice. And dozens of religious organizations, including Protestant, Roman Catholic and Jewish groups, have joined Americans United for Separation of Church and State in lobbying against the expansion.

"The concern that the founding fathers had about the separation of church and state was what the church might do to the state," Charles Moore, pastor of the Grace United Methodist Church in Austin, told a Texas newspaper. "Charitable Choice opens the door more than anything that I have seen in my lifetime to the church being able to take over the state and turn this nation into a theocracy."

Staff writer Joan Biskupic contributed to this report.