Organized by liberal-leaning evangelicals, some mainline Protestant clergy, and some Catholic groups, it will include Obama participating in a call-in program with religious leaders streamed on the Internet on August 19, prayer meetings and nationwide television ads.

Protestors have confronted members of Congress across the country in town hall meetings held to take the public pulse on the various healthcare overhaul plans being written in Congress.

What lawmakers found was anger fueled in part by Christian and conservative radio that healthcare would lead to taxpayer funded abortion and even euthanasia for the old, have incited much of the loudest and most dramatic reaction.

Some of the opposition is being fueled by leaders of the "religious right," the conservative Christian movement that remains a key base for the opposition Republican Party.

"I think that the Democrats were surprised by the strength of the religious right and the insurance companies and those opposed to healthcare reform when they got their grass roots efforts going," said Cal Jillson, a political scientist at Southern Methodist University in Dallas.