Clinton approaches the nominating season in a dominant position, leading Bush by 54 percent to 41 percent among registered voters and Romney by 55 percent to 40 percent.

Beyond Bush and Romney — the two Republicans who have made the firmest moves toward a 2016 run — Clinton holds equally large leads over other potential Republican hopefuls. She tops Rand Paul and Chris Christie by 13 percentage points each, and leads Mike Huckabee by 17 points.

Clinton’s husband, former president Bill Clinton, appears to create little drag on her potential.

Among all voting-age adults, more than 6 in 10 say the fact that Bill Clinton served as president has no bearing on whether they would support Hillary Clinton’s candidacy. And among those who say her spouse’s presidency will matter, 23 percent say it will make them more likely to support her, while 14 percent say less likely.