ZANESVILLE, Ohio – Sen. Barack Obama said Tuesday that if elected president he would expand the delivery of social services through churches and other religious organizations, vowing to achieve a goal he said President Bush had fallen short on during his two terms.

"The challenges we face today – from saving our planet to ending poverty – are simply too big for government to solve alone," Obama said, standing outside a community center here in eastern Ohio. "We need an all-hands-on-deck approach."

Some Democrats have previously backed similar efforts, but Bush's version, a centerpiece of his first-term agenda, has been a lightning rod for criticism from those concerned about the separation of church and state and those who argued that Bush had used it to further a conservative political agenda.

In embracing the same general approach as Bush, Obama ran the political risk of alienating those of his supporters who would prefer that government keep its distance from religion.

But Obama's plan departed from the Bush administration's stance on one fundamental issue: whether religious organizations that get federal funds for social services can take faith into account in their hiring. Bush has said yes. Obama said no.

"If you get a federal grant, you can't use that grant money to proselytize to the people you help and you can't discriminate against them – or against the people you hire – on the basis of their religion," Obama said. "Federal dollars that go directly to churches, temples, and mosques can only be used on secular programs."

Obama's position that religious organizations would not be able to consider religion in their hiring for such programs would constitute a deal-breaker for many evangelicals, said several evangelical leaders, who represent a political constituency Obama has been trying to court.

Evangelical leaders said that not allowing religious groups to hire on the basis of their beliefs would strip them of the very basis for the faith-based programs.

As he announced his proposal on Tuesday, Obama harked back to his early days as a community organizer in Chicago, where Catholic charities financed his programs.

"I didn't grow up in a particularly religious household, but my experience in Chicago showed me how faith and values could be an anchor in my life and an anchor in the community," Obama said, adding: "While I could sit in church and pray all I want, I wouldn't be fulfilling God's will unless I went out and did the Lord's work."