In a potential match-up with President Obama, former Massachusetts Gov. Mitt Romney (R) out-performs Sarah Palin (R) with some of the fastest-growing demographic groups, a new poll shows. 

Romney leads the former Alaska governor with unmarried women, minorities and young people, a group that has seen a 20 percent increase in the voting-age population in the last 10 years, according to Census data.

The group has been dubbed the "rising American electorate" (RAE) by Women's Voices. Women Vote, a Democratic advocacy group that commissioned the survey by Greenberg Quinlan Rosner  Research.

Obama led Palin by 38 points among RAE voters, but was ahead of Romney by only 25 points in the national survey of 1,480 voters.

The poll included an oversampling of 480 REA voters (200 unmarried women, 200 minorities and 80 youth) and had a margin of error of 2.55.

Moreover, married women gave Obama a 5-point edge against Palin (45 percent to 40 percent for Palin), but prefer Romney by a 51 percent to 43 percent margin, the survey found.

In 2008, married women went for Sen. John McCain (R-Ariz.) by single digits, Page Gardner, president of Women’s Voices, said on a conference call Monday, whereas 70 percent of unmarried women went for Obama.

In 2010, the group didn't return to the polls in the same numbers — whether they will again in the next election is unclear.

"They will determine the outcome of the 2012 election," said Gardner.

--Updated at 6:56 p.m. Jan. 25