Hillary Clinton leads all potential opponents in a new Washington Post/ABC News poll. (Nicholas Kamm/AFP/Getty Images)

Former Florida governor Jeb Bush now leads the field of prospective Republican candidates for the party’s 2016 presidential nomination, but former secretary of state Hillary Rodham Clinton enjoys a decided advantage over Bush and other potential GOP rivals in hypothetical general election matchups, according to a new Washington Post-ABC News poll.

At this early stage in the 2016 competition, the prospective candidates suffer from image weaknesses, but the Republicans have a more acute problem. Most Republicans are not well known, but at this point, not a single one of six Republicans included in the survey has a favorability rating that is net positive.

Bush — by far the best known among those running for the GOP nomination — is viewed favorably by 33 percent of the public, while 53 percent say they view him unfavorably. Only Clinton among all those included in the poll has a net positive rating, but by the slender margin of three percentage points (49 percent to 46 percent). Her favorability rating has dropped nine points in the past year and 18 points since she left the State Department in 2013.

Clinton stands now as the leading contender in either party for the White House, with no serious opposition at this point in the race for the Democratic nomination. But as she prepares to launch her campaign, she emerges also as a polarizing figure, with huge differences in the way she is perceived by Republicans and Democrats.

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Overall, she is seen as a strong leader and as someone with new ideas for the country. But on questions of honesty and trustworthiness, as well as on whether she understands people’s problems or shares the values of average Americans, the public is split almost evenly pro and con.

In the contest for the Republican nomination, Bush tops the field with 20 percent of Republicans and GOP-leaning independents saying they would support him if their primary or caucus were held today. He is followed by Sen. Ted Cruz of Texas at 13 percent and Wisconsin Gov. Scott Walker at 12 percent. Five other Republicans received at least 6 percent support, with an additional six candidates at either 2 percent or 1 percent. Bush, Cruz and Walker are the only three to register noticeable gains since the last Post-ABC survey on the GOP race in December.

Bush, who faces potential resistance from some Republicans for his stands on immigration and Common Core school standards, enjoys his strongest support among moderate and liberal Republicans and among those who say they are “somewhat conservative.”

Bush has been on an aggressive pace to stockpile funds for his candidacy and appears to have benefited from decisions by 2012 nominee Mitt Romney and 2012 vice-presidential nominee Rep. Paul Ryan (Wis.) to stay out of the race. His 20 percent support level, hardly an indication of dominance, underscores potential challenges ahead. But 1 in 3 Republicans say they think Bush will be their party’s nominee.

The survey was taken in the days after Cruz became the first Republican to formally announce a bid for the nomination. The former Texas solicitor general, running unabashedly as the true conservative in the race, enjoys his greatest support among the most conservative Republicans. Walker, who began rising after a well-received speech in Iowa in January, enjoys about equal support among those who say they are somewhat conservative and those who say they are very conservative.

Support for Bush and Cruz is mostly evenly distributed among demographic groups. Walker runs far better among men than women and far better among Republicans with college degrees than those without, although he did not graduate from college. Sen. Rand Paul of Kentucky, who hopes to redraw the GOP coalition, runs three times as well among those younger than 50 as among older voters.

Nearly all the Republican contenders are viewed favorably within their own party. Bush, Walker, Cruz and Sen. Marco Rubio of Florida, who is set to formally launch his campaign April 13, are viewed positively by margins of about 26 percentage points among self-identified Republicans. Paul, who plans to announce Tuesday, has a 13-point positive-to-negative rating in his party.

Meanwhile, New Jersey Gov. Chris Christie, once regarded as a top-tier prospect for the nomination, has a major image problem within his party as well as with the public at large. He is viewed favorably by 38 percent of Republicans and Republican-leaning ­independents and unfavorably by 41 percent. Among all poll respondents, 51 percent have an unfavorable impression of Christie, topped only by Bush’s 53 percent.

While Clinton’s image is stronger than those of Republicans, perceptions of her honesty and empathy have eroded as she has moved toward a 2016 presidential candidacy. Since last measured in June, as she began her tour to promote her State Department memoir, she has suffered a ­seven-point slip in perceptions of her honesty and an identical fall on the question of whether she understands the problems “of people like you.” Almost all of the decline came from more negative assessments among Republicans.

Among Democrats and Democratic-leaning independents, Clin­ton continues to hold a commanding lead in the competition for her party’s presidential nomination. She has a 6-to-1 advantage over Vice President Biden and Sen. Elizabeth Warren of Massachusetts, neither of whom has announced plans to run. Those who have expressed interest — former senator James Webb of Virginia, former Maryland governor Martin O’Malley and Sen. Bernard Sanders (I-Vt.) — are in the low single digits.

Tested against four possible Republicans in a general election — Bush, Cruz, Walker and Rubio — Clinton holds double-digit leads in every case. Bush does marginally better than the others but trails by 53 percent to 41 percent among registered voters, while Cruz runs weakest at 54 percent to 37 percent.

Clinton’s supporters are more passionate about their candidate than are Bush’s supporters. More than 8 in 10 Clinton supporters say they are enthusiastic, with more than 4 in 10 saying they are very enthusiastic. Among Bush supporters, while almost 7 in 10 say they are enthusiastic, just over 1 in 10 say they are very enthusiastic.

The Post-ABC poll was conducted March 26 to 29 among a random national sample of 1,003 adults interviewed by telephone, including 335 cellphone-only respondents. The overall margin of error is plus or minus 3.5 percentage points; the error margin is 5.5 percentage points among both the samples of 444 Republicans and GOP-leaning independents and 446 Democratic and Democratic-leaning independents.

Peyton Craighill contributed to this report.