Hillary Rodham Clinton holds a strong lead over other Democrats in the 2016 race, while the Republican field is wide open, a Washington Post-ABC News poll finds. (Sean Gardner/Getty Images)

Hillary Rodham Clinton holds a commanding 6 to 1 lead over other Democrats heading into the 2016 presidential campaign, while the Republican field is deeply divided with no clear front-runner, according to a new Washington Post-ABC News poll.

Clinton trounces her potential primary rivals with 73 percent of Democrats and Democratic-leaning independents, reinforcing a narrative of inevitability around her nomination if she runs. Vice President Biden is second with 12 percent, and Sen. Elizabeth Warren (Mass.) is third with 8 percent.

Although Clinton’s favorability rating has fallen since she stepped down as secretary of state a year ago, she has broad Democratic support across ideological, gender, ethnic and class lines. Her lead is the largest recorded in an early primary matchup in at least 30 years of Post-ABC polling.

The race for the Republican nomination, in contrast, is wide open, with six prospective candidates registering 10 percent to 20 percent support. No candidate has broad backing from both tea party activists and mainline Republicans, signaling potential fissures when the GOP picks a standard-bearer in 2016.

New Jersey Gov. Chris Christie, who was at or near the top of the Republican field in many public opinion surveys last year, appears to have suffered politically from the bridge-traffic scandal engulfing his administration.

The 2016 primaries and general election

The new survey puts Christie in third place — with the support of 13 percent of Republicans and Republican-leaning independents — behind Rep. Paul Ryan (Wis.) with 20 percent and former Florida governor Jeb Bush at 18 percent. The rest of the scattered pack includes Sens. Ted Cruz (Tex.), Rand Paul (Ky.) and Marco Rubio (Fla.), who are at 12, 11 and 10 percent, respectively.

Among strong backers of the tea party — who make up about one-fifth of the Republicans polled — Cruz has a big lead, with 28 percent, followed by Ryan, at 18 percent. But Cruz, an iconoclastic freshman senator who rose to prominence during last fall’s partial government shutdown, registers just 4 percent among those who oppose or have no opinion of the tea party.

Christie is weakest among the strong tea party set, winning 6 percent of that group, but he has the backing of 15 percent of other Republicans. Bush’s base of support comes from self-identified Republicans, while Ryan’s strength comes from white evangelical Protestants, young voters and less conservative wings of the party. Rubio does particularly well among Republicans with college degrees.

Christie has benefited from the perception that he has unique appeal among independents and some Democrats, a reputation the governor burnished with his 2013 reelection in his strongly Democratic state.

But that image has been tarnished, the survey finds. More Democrats now view Christie unfavorably than favorably, with independents divided. Republicans, meanwhile, have a lukewarm opinion, with 43 percent viewing him favorably and 33 percent unfavorably. Overall, 35 percent of Americans see him favorably and 40 percent unfavorably.

Christie’s administration is under investigation for a plot last fall to shut down local access lanes to the George Washington Bridge and cause four days of gridlock in Fort Lee, N.J., in an act of apparent political retribution against a Democratic mayor.

Among the public, 46 percent say they consider the bridge episode a “sign of broader problems” with Christie’s leadership, while 43 percent say they think it was an “isolated incident.”

Most Republicans give Christie the benefit of the doubt, with 57 percent saying the bridge incident is isolated. Sixty percent of Democrats say it is indicative of broader problems, while independents are almost evenly split.

The 2016 presidential campaign is not likely to start taking shape until the end of this year, when candidates are expected to begin declaring their intentions. Among the Republicans, Ryan and Bush appear to be the most ambivalent about a campaign. Other Republicans not named in the poll, such as Wisconsin Gov. Scott Walker, could gain steam as potential candidates.

On the Democratic side, Warren has said she will not run, although she has a loyal following among some liberal groups hoping to draft an alternative to Clinton.

Polling this far out in the cycle is poor at forecasting winners of party nomination battles, but it offers important clues about current voter attitudes. Major fundraisers and party activists in particular look to such polls as indications of potential candidates’ strengths and weaknesses on the national stage as they begin to pick their horses.

In a theoretical head-to-head general-election matchup, Clinton leads Christie among registered voters, 53 percent to 41 percent. This is a far larger deficit than Republicans had in the popular vote in the past two presidential elections. In 2012, President Obama beat Mitt Romney by 51 percent to 47 percent, and he beat John McCain by 53 percent to 46 percent in 2008.

Christie is hurt by weak support among independents — trailing Clinton by 48 percent to 43 percent — as well as by a less consolidated party base. Although 90 percent of Democrats say they would back Clinton, only 79 percent of Republicans say they would support Christie. By contrast, Romney beat Obama among independents by five percentage points, and he won 93 percent of Republican votes.

Clinton, who would become the first female president if elected, shows enormous strength among women in the new poll. She leads Christie among female voters by 59 percent to 34 percent — more than double the 11-point margin Obama held over Romney.

Christie tops Clinton by a slender three points among men, 49 percent to 46 percent; Romney won men by seven percentage points.

Clinton is buoyed by net-positive favorability ratings and by the intense loyalty of her supporters. Fifty-eight percent view her favorably , including 32 percent who are “strongly” favorable, while 38 percent have an unfavorable view of her.

This marks a decline from a Post-ABC poll last January, as Clinton prepared to leave the State Department. At the time, 67 percent said they viewed her favorably. The drop can be attributed to declining support among independents and Republicans, as Clinton inched back into partisan politics and the news media stopped covering her as a globe-trotting diplomat and focused on her presidential ambitions.

Still, Clinton’s current popularity is as high or higher than at any point during her eight-year tenure as a U.S. senator from New York, when her favorable rating in Post-ABC polling mostly hovered in the high 40s or low 50s.

Although Clinton was the front-runner heading into the 2008 primary season, she barely tipped over 50 percent in two Post-ABC surveys. Clinton’s standing heading into the 2016 Democratic primaries is considerably stronger. The poll shows her with remarkable strength across demographic groups. She wins nearly three-quarters of men and women, whites and nonwhites, young and old, as well as lower- and higher- income voters.

The Post-ABC poll was conducted Jan. 20-23 among a random national sample of 1,003 adults, including interviews on conventional telephones and with cellphone-only respondents. The overall margin of sampling error is plus or minus 3.5 percentage points.

Peyton M. Craighill contributed to this report.