Faith has emerged as a significant fault line in the Republican race for president, according to a new Washington Post-ABC News poll, which shows that Rick Santorum’s supporters seek a much stronger role for religion in American politics than do voters who support rival Mitt Romney.

More than half of Santorum’s backers say political leaders should rely on their religious beliefs while making policy decisions, but two out of three Romney supporters feel the opposite — that leaders should steer clear of their faith as they set policies for the country.

While 65 percent of Santorum’s supporters say it is important for a presidential candidate to share his or her religious beliefs, only about 40 percent of Romney’s supporters feel the same. And about six in 10 Santorum backers generally feel that the country has gone too far in separating church and state; 37 percent of Romney’s backers feel the same.

The results are consistent what has been evident in exit polls: Santorum, with his overtly Christian pitch, has emerged as the candidate of choice for religiously oriented Republican voters, particularly evangelical Christians, who have turned out in large numbers to support the Catholic former senator from Pennsylvania.

Romney, a Mormon who pursued moderate social policies as governor of Massachusetts, has struggled to connect with evangelical Christians, which has been a particular disadvantage for him in the South. About half of the GOP electorate thus far has identified as evangelical Christian, ranging from a low of 16 percent in Massachusetts to a high of 83 percent in Mississippi.

But Romney’s base’s opinions on religion in the public sphere, as well as their views on social issues, more closely resemble those of Americans at large. That finding reinforces the impression that Romney would have an advantage over Santorum in a general election.

Most Americans, some 63 percent, believe political leaders should not rely on their religious beliefs in making policy decisions, according to the new poll. About 58 percent say it does not matter if a candidate for president shares his or her religious views. Roughly one-third feel that the country has gone too far in keeping church and state separate; another third feel that the nation has struck a good balance.

While overwhelming majorities of Santorum’s supporters believe abortion and same-sex marriage should be illegal, Romney’s backers are more divided on those hot-button issues, mirroring the country at large.

Nationally, 54 percent of U.S. adults believe abortion should be legal and slightly more than half support legalizing same-sex marriage, according to the new poll. The views on abortion are largely unchanged from polls dating at least back to the 1990s. Opinions on the legalization of same-sex marriage have shifted sharply in the past decade, with a slight majority in favor of it since last year.

Though Santorum has gained traction among evangelical Christians, he has not had the same advantage with his fellow Catholics, whose views on social issues more closely match the national average.

While nearly 60 percent of white evangelical Protestants think the country has gone too far in separating church and state, about half as many white Catholics share that view, according to the poll.

About six in 10 white Catholics believe abortion should be legal, and a similar proportion supports same-sex marriage, despite their church’s teachings to the contrary.