A national political group for gays is staging mock "retirement parties" for Sen. Rick Santorum (search) as part of a campaign to defeat the high-ranking Republican next year.

The Washington-based National Stonewall Democrats (search) and its local chapters have signed up hosts for about 40 parties in more than a dozen states, including six in Santorum's home state of Pennsylvania. Most of the parties are scheduled for Nov. 13.

Organizers say their main goal is to energize rank-and-file activists for next year's campaigns and the 2008 presidential election.

Santorum, who as GOP conference chairman is the Senate's third-ranking Republican, helped lead last year's unsuccessful push in Congress for a constitutional ban on gay marriage (search).

In a 2003 interview with The Associated Press, he angered gay-rights groups by saying states should have the right to ban gay sex and by comparing homosexuality to bigamy, incest and adultery.

Santorum campaign spokeswoman Virginia Davis said the senator believes marriage should be "between one man and one woman" and that "special rights should not be granted based on sexual orientation."

She added that he "respects the rights of groups who wish to express their First Amendment rights."

An independent poll conducted by Connecticut-based Quinnipiac University last month showed Santorum trailing Democratic state Treasurer Robert P. Casey Jr., 52 percent to 34 percent. The survey had a sampling error margin of plus or minus 2.5 percentage points.

Both men are expected to face primary opposition.

Casey supports laws banning discrimination on the basis of sexual orientation and favors allowing same-sex couples to join in civil unions.

The Log Cabin Republicans — a GOP-oriented political group for gays — will not endorse Santorum's re-election bid, a spokesman said.