Just one day after former Florida Gov. Jeb Bush all but announced a bid for the presidency in 2016, a new poll has found that a majority of Americans say they couldn't support him.According to an NBC News/Wall Street Journal poll conducted Dec. 10-14 of 1,000 adults, 57 percent of voters say they couldn't support him, compared to just 31 percent who said they could see themselves backing Bush in 2016.Other potential GOP candidates also do not fare well.Sixty percent of those surveyed said they could not support 2012 Republican nominee Mitt Romney, while 53 percent said they couldn't vote for New Jersey Gov. Chris Christie.Former Secretary of State Hillary Clinton emerged from the poll as the frontrunner, with 50 percent of voters saying they could see themselves voting for her, compared to 48 percent who oppose her."Despite these numbers — which could certainly change as the presidential field becomes clearer — Clinton is far from a lock on the presidency," NBC News said.NBC News noted that 71 percent of voters said they want the next president to take a different approach than President Barack Obama, yet Clinton is strongly tied to the administration, having served in it.Meanwhile, 40 percent of voters in the poll said they prefer a Republican to be the next president, compared to 38 percent who do not."This is an electorate — by a large margin — looking for change," said Republican pollster Bill McInturff, who conducted this survey with Democratic pollster Peter Hart, according to NBC News.Among Republican voters who will determine the eventual nominee, Romney gets the most support with 63 percent compared to 33 percent. Bush would attract 55 percent support compared to 34 percent of the GOP who would oppose him.Former Arkansas Gov. Mike Huckabee is in third place with 47 percent support compared to 39 percent who would not back him. And Kentucky Sen. Rand Paul would attract 47 percent support compared to 34 percent who would not vote for him.The poll also found that more Republicans oppose Christie than support him, with 43 percent against him compared to 40 percent who would support him, NBC News reported.