The decision here in Texas came on the eve of the final Sunday church services before the South Carolina primary on Saturday. Mr. Santorum said that he raised $3 million in the last week and expected that the support would likely help him raise even more money and strengthen his campaign organization in the state.

“People are trying to assess not just who’s the most electable conservative, vis-à-vis Mitt Romney, but who’s the most electable, period,” Mr. Santorum said Saturday, adding that he was “not going to call on anybody to drop out of the race.”

The moment that word spread about the decision in Texas, allies of Mr. Gingrich forcefully pushed back against the suggestion that Mr. Santorum won the group’s support outright. They noted that many evangelical leaders remain firmly divided and have little sway over their congregations or members.

The power of the support for Mr. Santorum will be tested over the next seven days in South Carolina. In the Republican presidential primary there four years ago, exit polls found that 60 percent of voters said they considered themselves “born again” or evangelical Christians.

Evangelicals tend to be better informed and more independent that they were a generation ago, when the endorsement from a leader like Jerry Falwell or Pat Robertson held huge sway, said Rev. Paul Jimenez, pastor of Taylors First Baptist Church in Greenville, S.C.

“People will take note of what the leaders say, but the days are gone when you could stand up and say this is our guy,” said Mr. Jimenez, who previously worked in Washington for the late Senator Jesse Helms of North Carolina. “Evangelicals have so many voices now.”

But organizers of the Texas meeting said they expected to see new endorsements and fund-raising efforts for Mr. Santorum before Republicans in South Carolina vote on Saturday, followed by the Florida primary on Jan 31. Their hope is that if evangelicals unite around one candidate, they can head off the nomination of Mr. Romney, whom they regard as too moderate.