Abortion, same-sex marriage, stem-cell research and school prayer have been reliable “wedge issues” for the Republican Party since 1972, when President Nixon announced his opposition to “unrestricted abortion.” Nixon won reelection with 60 percent of the Catholic vote, a previously reliably Democratic constituency.

At the 1992 GOP convention, one of Nixon’s former aides, presidential candidate Pat Buchanan, introduced the powerful phrase “culture wars.”

The events of the last two weeks prove that the culture wars are still with us. And with the economy improving, the search is on for new wedge issues to help the GOP in the 2012 campaign.

Here are some contenders:

• A federal appeals court in California overturned the state’s ban on same-sex marriage. That opens the door to a Supreme Court ruling and a divisive issue for the presidential candidates.

• The king of wedge issues — abortion — is back in the news after the Susan G. Komen Foundation cut support for Planned Parenthood based on a House investigation into its abortion services.

• But the big contender for the culture war crown is the Obama administration’s requirement that all employers, even schools and hospitals affiliated with the Catholic Church, provide birth control services as part of their healthcare insurance coverage.

Leaders in the Catholic Church have been vocal in their opposition to the rule, citing tenets of their faith that prohibit birth control.

At last weekend’s Conservative Political Action Conference, all the Republican candidates took hard right stands to prove their conservative credentials.

Newt Gingrich repeated his charge that the incumbent is waging a “war against religion.”

Mitt Romney railed against the health care requirement as “a violation of conscience.”

Former Pennsylvania Sen. Rick Santorum accused President Obama of crushing First Amendment protections of religious liberty.

The political irony here is that this culture war over insurance coverage for contraception shows little evidence of winning votes for Republicans — even among Catholics.

As a wedge issue it is a political pretender.

The health care law already exempts churches. It did cover hospitals and schools but late last week Obama allowed those church-affiliated institutions to distance themselves from providing birth control. Instead, insurance companies will offer coverage at no extra cost.

Even before the president accommodated the Catholic bishops, it was clear there was no issue there. Most states already have such laws. To quote Sen. Richard Blumenthal (D-Conn.), the law never required anyone to “use birth control” and “no institution is required to dispense it.” The only requirement was to offer contraception as part of health care coverage.

A Public Religion Research Institute poll released last week found that 58 percent of Catholics believe employers should provide employees with contraception as part of their health care plans.

Another poll — this one from Fox News — found 61 percent approval for the original provision. A similar poll by Public Policy Polling found that 62 percent of Catholics who identified themselves as independents supported it. A survey from the pro-choice group Catholics for Choice found that 98 percent of Catholic women have used contraception at some point in their lives.

“I am dumbfounded that in the year 2012 we are still fighting about birth control,” Sen. Kirsten Gillibrand (D-N.Y.) said at a news conference. “The power to decide whether or not to use contraception lies with a woman — not her boss,” she said. Who can disagree with that?

So, what is this political fight about?

At best it fires up the conservative GOP base. But absent a major shift in public opinion, the issue lacks the critical power to win over Catholics, independents and socially conservative Democrats to the Republican side.

One possible target is the Hispanic voter. That heavily Catholic population might be swayed by their loyalty to the church hierarchy. And Hispanics are a critical vote in several swing states, from Florida to Colorado. But out-of-wedlock births and teenagers giving birth are major problems among Hispanics. Again, for all the huffing and puffing, the issue lacks political bite.

Republican nominee John McCain lost the votes of women to Obama by 13 percent in 2008. If the GOP candidate this year runs aggressively against universal coverage for birth control, that gulf will increase to a Grand Canyon.

The same is true of the gay marriage issue. Polls show too many Americans, including younger conservatives, are not opposed to the idea. It is lacking as a political wedge.

Similarly, the Komen Foundation’s attack on Planned Parenthood’s work in breast cancer screening — because of the congressional probe into its abortion work — turned into a political disaster for Komen. Planned Parenthood reported a surge in donations.

There are two ends to every wedge. At the moment the GOP is sliding down these wedges. But the search goes on.

Juan Williams is a writer, author and Fox News political analyst. His latest book "Muzzled: The Assault On Honest Debate" (Crown/Random House) was released in July. This column originally appeared on The Hill.com.