Mitt Romney, the Republican Party's unsuccessful presidential nominee in 2012, leads the field for the 2016 election among Republican voters, according to a Quinnipiac University poll released on Wednesday.

The former Massachusetts governor would have a slight edge over potential Democratic candidate Hillary Rodham Clinton by 45 percent to 44 percent in a general election, the poll found.

Among possible Republican candidates, Romney's 19 percent put him ahead of former Florida governor Jeb Bush with 11 percent, New Jersey Gov. Chris Christie and Ben Carson each with 8 percent each, and U.S. Sen. Rand Paul of Kentucky with 6 percent.

Carson, a former neurosurgeon with no political experience, is a conservative commentator and author of "One Nation," which topped the New York Times best-seller list in June.

U.S. Rep. Paul Ryan of Wisconsin, U.S. Sen. Ted Cruz of Texas, Wisconsin Gov. Scott Walker and former Arkansas Gov. Mike Huckabee all had 5 percent, while 16 percent of those questioned were undecided.

With Romney out of the picture, Bush polled 14 percent with Christie at 11 percent and Carson at 9 percent.

Clinton, the former secretary of state, dominated the field for Democratic voters in the poll with 57 percent, followed by U.S. Sen. Elizabeth Warren of Massachusetts with 13 percent and Vice President Joe Biden with 9 percent.

The telephone poll, taken Nov. 18-23, questioned 707 Republicans and 610 Democrats with a margin of error of about 4 percentage points.