We understand that Mitt Romney almost certainly won't run for president as an independent this year. There are a lot of reasons why not, including the fact that Romney has given almost no indication that he plans to do so. (Another reason: Any independent candidate needs to hustle if he or she wants to get on the ballot in enough states to make a difference.)
So think of the inclusion of Romney in a potential three-way matchup against Donald Trump and Hillary Clinton in the most recent poll conducted by The Washington Post and ABC News as sort of an ideal, non-Trump candidate. This isn't Gary "Who?" Johnson, whose anonymity probably muffles the accuracy of how he might fare over the course of the campaign as the Libertarian Party candidate. This is Romney, a guy who ran in 2008 and 2012, and who has the name ID that comes with that.
How does Romney do, in this hypothetical matchup? He comes in third, which probably doesn't come as much of a surprise. Without Romney in the race, Trump leads Clinton by 2 points among registered voters, 46-44. With Romney? Clinton leads by 2, getting 37 percent to Trump's 35 — and Romney's 22.
Where did Romney's support come from? It came from some Clinton supporters, but significantly more Trump ones. Twenty-four percent of those who backed Trump in a one-on-one race jump ship to back the former Massachusetts governor.
A lot of that support comes from independents, with about a quarter of that group choosing Romney. But a full third of Republicans would back Romney over Trump if he were on the ballot.
Why? There's a simple explanation. More than 90 percent of Republicans who backed Trump in the primary support him in the three-way contest. But among Republicans (and independents who voted in the Republican primaries) who didn't back Trump, the vote with Romney is almost equally split, with Trump getting only about half of that group.
Among Republicans who view Trump somewhat favorably, Romney still gets more than a third of support. Among those who view him very negatively, two-thirds would prefer the 2012 GOP nominee to the 2016 one.
Again: This matchup isn't going to happen. And again: We can't say that a similar split doesn't exist on the Democratic side. What we do know is that, while Trump's new, small lead is probably thanks to Republicans consolidating around him, if there were another choice not named Clinton, that probably wouldn't be the case.