WASHINGTON - Jeb Bush, who is seriously considering a 2016 presidential bid, has sprinted to the front of the Republican field in a new McClatchy-Marist Poll.

Former GOP nominee Mitt Romney remains on top, with Bush, a former Florida governor, a close second. Take away Romney, and Bush leads the field.

The poll also found anxious Democrats increasingly eager to change course from President Obama. Fifty-eight percent of Democrats want a nominee who will move in a different direction from Obama, up 10 percentage points from a year ago.

But that hasn't translated - at least not yet - into any surge of support for a new face: Hillary Rodham Clinton leads by large margins over any potential challengers for the Democratic nomination, including Sen. Elizabeth Warren (D., Mass.), the emerging voice of the liberal wing in Congress.

Right now, the action in the early presidential campaign is on the Republican side, and, as it has in five elections in the last half century, it involves a member of the Bush family. (George H.W. Bush ran for president in 1980, 1988, and 1992; George W. Bush ran in 2000 and 2004.)

Jeb Bush has been sending strong signals that he might run for the 2016 nomination. Early next year, he plans to release a book, as well as 250,000 e-mails from his two terms as governor, a possible precursor to a run.

"I think I would be a good president," he said in a Miami television interview Sunday.

If he's in, Romney probably isn't, since they would tap the same establishment campaign and funding sources. Bush has said he will decide soon.

If Romney did run, the poll found that he would be supported today by 19 percent of Republicans and Republican independents, followed by Bush with 14 percent.

They would be followed by Gov. Christie of New Jersey and former Gov. Mike Huckabee of Arkansas, each with 9 percent, and physician Ben Carson with 8 percent. The rest of the potential field trails in smaller single digits.

If Romney didn't run, Bush would lead with 16 percent, followed by Huckabee with 12, Christie with 10, and Carson with 8.

Again, the rest of the potential field trails in smaller single digits. It includes Rep. Paul Ryan of Wisconsin, 7 percent; Sen. Rand Paul of Kentucky, 6 percent; Sen. Ted Cruz and Gov. Rick Perry, both of Texas and each with 5 percent; Sen. Marco Rubio of Florida, Gov. Scott Walker of Wisconsin, Gov. John Kasich of Ohio and former Sen. Rick Santorum of Pennsylvania, each with 3 percent; Gov. Bobby Jindal of Louisiana and businesswoman Carly Fiorina, each with 1 percent.

Among Democrats, former Secretary of State Clinton remained far ahead of potential challengers. No one came close to her 62 percent support. Vice President Biden had 11 percent.

Warren, who says she isn't running, would get 9 percent today. Even among those who said they were very liberal, she won 11 percent to Clinton's 62 percent. Warren did best among independents, with 15 percent to Clinton's 56 percent.

Clinton may be well-positioned to take advantage of that mood, Miringoff said. She left the Obama administration nearly two years ago, has been somewhat critical of his foreign policy, "and she can say she ran against the guy in 2008," he said.

Clinton easily defeated every potential Republican challenger in general election matchups. She rolled up margins of 13 percentage points over Bush, 12 over Christie and Romney, and 14 over Paul. Notable: At a time when Democrats have had trouble wooing white voters, Clinton runs roughly even with the Republicans.

The survey of 1,140 adults was conducted Dec. 3-9 by the Marist Poll, sponsored in partnership with McClatchy. Results are statistically significant within 2.9 percentage points.