More than 100 big-name Republicans have signed a new brief urging the Supreme Court to codify the right to gay marriage in one of the biggest shifts toward embracing gay marriage in the recent history of the GOP.

But while significant, the shift is less than meets the eye.

The fact is that the vast majority of the signers are no longer in office or never were and don't have to worry about their next election (New York Rep. Richard Hanna and Florida Rep. Ileana Ros-Lehtinen are the only federal officeholders on the list). For Republicans who have to face their party's voters ever few years, it's a much harder hill to climb, and that will prevent the larger party from embracing gay marriage any time soon.

While we've seen many national Republican politicians move to support gay marriage in recent years — from Dick Cheney to Laura Bush to Colin Powell to former RNC chairman Ken Mehlman — the party base hasn't really moved with them all that much.

As the chart below shows (based on data from Pew), Democrats and independents have moved significantly more toward embracing gay marriage over the past decade than Republicans have.


While Democratic support for gay marriage has jumped 19 percent since 2001 and independents have moved from 43 percent to 52 percent, Republicans have barely moved on the issue, from 21 percent to 24 percent.

A November Washington Post-ABC News poll showed GOP support for gay marriage was a little higher — 31 percent — but also that two-thirds oppose it.

Perhaps most striking is that a clear majority of Republicans — 54 percent — opposed gay marriage strongly. And among those describing themselves as "conservatives," 68 percent said they oppose gay marriage strongly.

In other words, a majority of the GOP is firmly entrenched in the anti-gay marriage camp and won't be budging any time soon. And the party's base feels very strongly about this issue.

Gay marriage, as with other social issues like illegal immigration, is now pitting the party base against the party's long-term political prospects. If the party wants to appeal to independents — especially young people who support gay marriage much more than the older generations — gay marriage is increasingly part of the deal. It's pretty swiftly becoming the new normal.

But that doesn't mean the party is going to move en masse toward gay marriage. The fact is that any Republican officeholder who supports gay marriage is basically begging for a primary challenge, and that's why very few have.