Obama-Biden 2012? How about an Obama-Onan ticket?

No, Onan isn’t some hot new pol. He was slain by God about 3,700 years ago after committing an act of contraception.

Now that Obama has mandated insurance companies pay for contraception, Onan is essentially part of the president’s reelection campaign as Republicans — particularly those in Florida — have made the requirement a strategic political issue.

U.S. Sen. Marco Rubio is sponsoring legislation to repeal the Obama-ception rule. Republican Party of Florida Chairman Lenny Curry said it was anti-free market. And Florida Attorney General Pam Bondi penned a letter with 11 colleagues from other states to “vigorously oppose it in court.”

“Not only is the proposed contraceptive coverage mandate for religious employers bad policy, it is unconstitutional,” Bondi and others wrote, warning that “sterilization and related services” would also be covered. “It conflicts with the most basic elements of the freedoms of religion, speech, and association, as provided under the First Amendment..”

But, liberals say, Republicans are picking the wrong fight and are overreaching.

“I can hardly believe our luck that Republicans want to litigate birth control at the polls,” Markos Moulitsas, one of the most-progressive voices of the blogosphere, tweeted last week. “The best part about this birth control debate is that Republicans think they’re actually winning it.”

Polling indicates both sides might be right because survey responses partly depend on how an issue is framed or asked.

This is campaign season. And campaigns are about selling ideas and changing minds.

More than likely, if Obama’s mandate is sold by Republicans as an issue of religious liberty, he loses. If it’s sold by Democrats as an issue of women’s health, he wins.

Right now, though, it looks like Democrats might be getting the upper hand in the message war. Most major polling indicates that most voters — even Catholics — support the president’s mandate.

Catholics are key — and not just because they’re one of the only major branches of Christianity to doctrinally oppose contraception, due in part to the story of Onan in Genesis. Catholics, who backed Obama in ’08, are overwhelmingly white and Hispanic. Whites are the biggest bloc of voters, and those who identify themselves as Hispanics — an ethnicity, not a race, mind you — are the fastest-growing segment of the electorate.

So, for the first time since John F. Kennedy’s election, talking Catholics is cool in politics. As go Catholics, so can go the political spoils.

Polling data from the conservative-leaning Rasmussen Reports indicated that 65 percent of Catholics opposed the contraception requirement and that 68 percent of Catholics disapproved of the president’s job performance.

Overall, Rasmussen found, 50 percent of all likely voters opposed Obama’s mandate, while only 39 percent agreed.

The poll’s wording is key. It asked people whether they supported the requirement even though it “violates deeply held beliefs of some churches.” It’s certainly disputable among “sexually experienced” Catholic women, 98 percent of whom had used contraception at least once, according to one survey.

Unlike Rasmussen, though, the more-neutral Gallup Poll found that Obama’s support among Catholics was about the same as the rest of the nation: 47 percent.