In a New York Times/CBS News poll conducted in March with 1,362 adults, 12 percent of Republicans and 34 percent of Democrats said gay couples should be allowed to legally marry. Thirty seven percent of Republicans and 41 percent of Democrats said gay couple should be allowed to form civil unions but not allowed to marry. More than half of Republicans -- 52 percent -- and 30 percent of Democrats said there should be no legal recognition of a gay couple’s relationship at all. The nationwide telephone poll has a margin of sampling error of plus or minus three percentage points.

At this stage in a presidential campaign, candidates are typically concentrating on winning over the most ideologically motivated members of their parties, assuming that they are the ones most likely to turn out to vote in the primaries. Any moves to the middle, the thinking goes, can come once the nomination is secure.

But this time, some candidates are challenging ideological orthodoxy in a way that suggests they are willing to gamble that social issues do not pack the punch they once did. Rudolph W. Giuliani, the former New York City mayor who is seeking the Republican nomination, has reaffirmed his support for abortion rights. Senator John McCain, the Arizona Republican, is bucking many in his party by backing an overhaul of the immigration system that would allow millions of illegal immigrants a chance to become citizens.

Their positions suggest that candidates and campaign strategists, always on the hunt for the new new thing, may have found it in the great swath of the American middle. It is not just abortion. There is a consensus on other social issues as well including health care, the environment and immigration.

Matthew Dowd, one of the chief strategists of George W. Bush’s 2004 re-election campaign, and now a partner in the firm Vianovo, said there is a consensus on many of these issues and noted that people are “tired of the polarized discourse and just don’t want the debate.”

“People don’t want social issues thrown at their doorstep anymore —- abortion, gay marriage, Terry Schiavo,” said Mr. Dowd. “People in the middle say yeah, these are tough personal decisions but we have a structure for dealing with them so why are politicians bringing this up.” He added, “In their mind, things like the abortion debate are settled.”

Mr. Dowd, who advised Arnold Schwarzenegger in the California governor’s race, said, “Someone who thinks they have to go left or right on an issue is running a race that’s gone.”