WASHINGTON -- Businessman Herman Cain and former Massachusetts governor Mitt Romney are running nearly even atop the field of 2012 GOP presidential hopefuls, a new Washington Post-ABC News poll shows, with most Republicans dismissing the harassment allegations that over the past week have roiled Cain's campaign.

Seven in 10 Republicans say reports that Cain made unwanted advances toward two employees when he was head of the National Restaurant Association in the 1990s -- allegations that have been stiffly rebutted by Cain's campaign -- do not matter when it comes to picking a candidate.

But the potential threat to his burgeoning campaign is evident as well, with Cain slipping to third place among those who see the charges as serious, and Republican women significantly more likely than men to say the scandal makes them less apt to support Cain.

The poll was conducted Oct. 31-Nov. 3, starting the evening after Politico first reported the harassment allegations. Support for Cain was basically steady over the four nights of interviewing, even as new charges against him surfaced.

Nearly a quarter of all Republicans and GOP-leaning independents now back Cain as the party's nominee, his best showing in Post-ABC polls this year, and up significantly from early October. At 23 percent nationally, Cain is neck and neck with Romney (24 percent) atop the GOP field.

"I think (the charges against Cain are) mostly garbage that they throw at people who want to be president," James Kindsch of Middleton, Wis., said in a follow-up interview.

"I don't believe it," said Paul Bradley of Fishersville, Va., adding, "The further in the past they happened, the less accurate they are."

A total of 1,004 telephone interviews were conducted, including a sample of 438 Republicans and GOP-leaning independents.

The margin of sampling error for this smaller sample is plus or minus 5.5 percentage points.

Tuesday's Rasmussen poll of 770 likely primary voters:

Cain 33%

Romney 23%

Gingrich 15%

Undecided 10%

Perry 9%

Paul 5%

Bachmann 2%

Huntsman 1%

Santorum 1%

Other 1%