Most voters say same-sex marriage should be decided by the U.S. Constitution, even as many pols have suggested that individual states should determine whether it ought to be legal.

(Matt McClain/The Washington Post)

In a new Quinnipiac University survey released Thursday, 56 percent said that same-sex marriage should be decided for all states on the basis of the Constitution. Just 36 percent said states should make the call.

The survey’s findings reflect the data in a March Washington Post-ABC News poll. Fully 64 percent of Americans and 62 percent of registered voters said the legality of same-sex marriage should be decided by the Constitution.

In the Quinnipiac poll, nearly seven in 10 Democrats support a constitutional decision. Republicans are more divided, with 49 percent siding with the states and 45 percent preferring a constitutional mandate. The Post-ABC poll also shows stronger support among Democrats for a federal directive, though a majority of Republicans (54 percent) also said they prefer a constitutional decision.

A constitutional preference doesn't necessarily mean someone is in favor of gay marriage, it’s important to note. The Republican Party's platform calls for a constitutional amendment defining marriage as between a man and a woman, for example.

Despite the public’s preference for a federal decision, lawmakers in both parties continue to say that the issue should be decided by the states.

“Senator Heitkamp believes this should be decided on a state-by-state basis,” said a spokesperson for Democratic Sen. Heidi Heitkamp of North Dakota, one of only seven Senate Democrats who have not come out in support same-sex marriage.

"According to the U.S. Constitution, marriage and family law are reserved for the states," said Sen. Mary Landrieu (D-La.), another red state Democratic senator who hasn’t come out in favor of gay marriage.

Sen. Marco Rubio (R-Fla.) also believes states have the right to define marriage. “Just because I believe states should have the right to define marriage in a traditional way does not make me a bigot,” he said in a speech last month.

While they are at odds with most voters, it’s not a total surprise that these and other pols continue to adopt a “let the states decide” posture. Conservative rhetoric – especially coming from those outside of Washington – often involves a federalist argument that resonates heavily with with the political right. If you're a Democrat in red state, it's politically perilous to part ways with conservatives, if you're hoping to win the crossover votes necessary for political survival.

What’s more, at a time when Washington is unpopular, it’s easier to rail against the federal government infringing on local territory on just about every issue. Same-sex marriage has proven to be no exception.