Cultural conservatives have yet to rally behind any one Republican presidential candidate, a dynamic that could benefit Mitt Romney.

If his rivals manage to split this critical segment of the GOP base, the former Massachusetts governor could be handed an important victory.

That's a scenario that will be playing out on the campaign trail and in Washington over the weekend during a two-day gathering of conservatives who care deeply about social issues, like abortion and gay marriage.

On Friday, the candidates with the best hopes of winning conservatives' support are set to speak at the Values Voters Summit. Former Pennsylvania Sen. Rick Santorum, Texas Gov. Rick Perry, businessman Herman Cain, former House Speaker Newt Gingrich of Georgia and Minnesota Rep. Michele Bachmann will all address the gathering.

Romney and libertarian Rep. Ron Paul of Texas won't speak until Saturday; neither has drawn strong support from cultural conservatives in the past. Former Utah Gov. Jon Huntsman isn't even going to attend.

The others have made direct and repeated appeals to the religious right as they pursue the nomination. Bachmann often discusses her own faith journey _ she became a born-again Christian at the age of 16. Santorum developed a strong anti-abortion reputation when he served in the Senate, and he argues he's lead on that position for longer than the other candidates. Businessman Herman Cain has recently surged in polls as his message has caught on with conservative voters. Perry, Romney's chief rival, has discussed his faith at length in public. This summer, he hosted the Response, a prayer rally that drew more than 20,000 people to a Houston football stadium.

If they are successful, it could split the socially conservative vote in critical early voting states like Iowa and South Carolina. That would pave the way for Romney, who could capture strong finishes without earning a majority of GOP support.

At the conference Friday, Santorum was set to speak first, followed by Perry, Cain, Gingrich and Bachmann.