Republican former presidential nominee Mitt Romney speaks at a campaign event for Senate candidate Scott Brown at Gilchrist Metal Fabricating in Hudson, N.H., earlier this month. (Brian Snyder/Reuters)

When Mitt Romney managed to get about 25 percent support in the early polls against his 2012 Republican rivals, everyone asked, “What’s wrong with Mitt?” He was, after all, the presumed front-runner. Today, with a new Washington Post-ABC News poll showing something similar about 2016, the question could be, “What’s wrong with all the others?”

The survey tested Romney against the prospective field of 2016 GOP presidential candidates. Ann Romney told Maeve Reston of the Los Angeles Times last week that she and the Romneys’ sons are “done, done, done” with presidential politics after two failed campaigns. But for now, the former Massachusetts governor and 2012 nominee is at the top of the heap in the eyes of rank-and-file Republicans.

The Post-ABC poll found that 21 percent of Republicans or Republican-leaning independents say they favor the Romney as their 2016 nominee. That was almost double the 11 percent who named the person in second place, former Florida governor Jeb Bush.

Romney benefits as much or more from the fact that no one among the likely candidates has yet filled the vacuum he left behind. That he enjoys top billing among prospective 2016 GOP candidates says something about Romney but much more about the others in the unsettled field.

Romney enjoys a warm glow today in part because of what’s happened to President Obama since 2012. Remembered are attributes or statements that look better in retrospect than they did at the time. Forgotten or dismissed are some of the mistakes Romney made in that campaign, from “self-deportation” to “47 percent.”

Question marks

With the assumption that Romney would not run again, the 2016 race always was going to look different than past Republican nominating contests. For the first time in a long time, there is neither an heir apparent (George H.W. Bush in 1988, Bob Dole in 1996, John McCain in 2008, Romney in 2012) nor a dominant first-time candidate (George W. Bush in 2000).

Republicans assumed their 2016 field collectively would be far stronger than the group who competed in 2012, which is now regarded as one of the weakest in modern times. That could still turn out to be the case, but so far no one has begun to break from the pack.

The Post-ABC poll highlights this. Taking Mitt and Ann Romney at their word that a third campaign is not in their future, this race is as wide open as it could be, at least in terms of early popular support.

Absent Romney, Jeb Bush leads with a mere 15 percent, Sen. Rand Paul (Ky.) is second at 12 percent, and former Arkansas governor Mike Huckabee is third at 11 percent — all within the five-point error margin.

After that, in descending order, are the single-digit candidates, all bunched between 8 and 6 percent: Rep. Paul Ryan (Wis.), Sen. Marco Rubio (Fla.), New Jersey Gov. Chris Christie, Ben Carson and Texas Gov. Rick Perry. Coming in below 5 percent are Sen. Ted Cruz (Tex.), former senator Rick Santorum (Pa.), Louisiana Gov. Bobby Jindal, Ohio Gov. John Kasich and, at 1 percent, Wisconsin Gov. Scott Walker.

Bush’s support is fairly even through various demographic and economic groups. Huckabee is stronger among women than men, while Rand Paul is the opposite. Paul Ryan does better with Republicans who have college degrees or incomes over $50,000 than he does with those without degrees and making less.

On perhaps the most important divide within the GOP, Bush does significantly better among Republicans who say they do not support the tea party, as befits his establishment pedigree. Huckabee and Paul do better with the much larger group of Republicans who say they back the tea party movement.

Any analysis of 2016 polls comes with the obvious caution: Given the number of candidates and the absence of a clear front-runner, these early measures are far from predictive. Beyond that, they can’t measure the fundraising wherewithal or the political staying power each candidate could bring to a campaign. Because they are national surveys, they don’t take into account strengths or weaknesses in the early states that winnow the field. Most significantly, they don’t measure the quality of campaigning skills.

Examples abound from past campaigns to underscore those caveats.

Huckabee won the Iowa caucuses in 2008, but his campaign was always crippled by lack of money. Hillary Rodham Clinton had great national numbers in 2007 but always looked vulnerable in polls of Iowa Democrats. Perry is Exhibit A of the difference between how a candidate looks on paper and on the campaign trail.

If he decides to run, Bush should be able to raise the money needed, but he is at odds with his party’s base on some key issues, and according to a recent Des Moines Register-Bloomberg Politics poll of Iowa Republicans, he comes in with just 4 percent support in the state whose caucuses kick off the process. The biggest question mark is whether he will even seek the nomination.

Others in the prospective field have even bigger question marks behind their names. Simply put, how many of the prospective candidates look better as this midterm election nears its conclusion than they did in the months right after the 2012 campaign? Readers can draw their own conclusions based on what they’ve seen so far.

Ready for Hillary

On the Democratic side, there are no surprises. It’s still Clinton vs. all others.

In the latest survey, 65 percent of Democrats and Democratic-leaning independents say they favor the former senator and secretary of state for the nomination. Vice President Biden is second at 13 percent, with Sen. Elizabeth Warren (Mass.), who has said repeatedly she has no intention of running, at 10 percent.

Although Clinton’s support is strong through all demographic and economic groups, there are some variations of note. She enjoys far more support among women than men and stronger support among Democrats 50 or older rather than among those younger.

Clinton also wins demonstrably more support among white Christians than among those who say they have no religion. And she does better with white Democrats who do not have a college degree than with those who do. In that way, her profile differs from that of Obama, who has generally done better with voters who have college degrees and post-graduate degrees than those without.

That could prove significant in a general election. If that profile was to translate into her capturing a higher share of the white vote in a general election than Obama managed in 2012 while retaining the Obama coalition of minorities and well-educated whites, Republicans would be in trouble, unless they can offset it by doing better among non-white voters. First, however, they will have to find a candidate.