Gingrich: The Santorum Siphon?

We've been gathering string from the Super Tuesday exit poll and related surveys the past two days. One result - on the Santorum/Gingrich debate - is worth recounting here, and we'll follow with more down the line.

So: Is Newt Gingrich tripping up Rick Santorum by siphoning away anti-Romney voters?

It's hard to answer, because it's hypothetical; we haven't had a second-choice question in any of the exit polls this year. But the data we do see suggest that this argument, at best, is far from a slam-dunk.

First, in our ABC News/Washington Post pre-election polls, among leaned Republicans nationally, Gingrich supporters have been somewhat more apt to pick Mitt Romney rather than Santorum as their second choice. These are all Republicans and GOP-leaning independents, not just primary voters, but it doesn't help the Santorum-siphon argument.

Cutting more to the chase, exit polls suggest that Gingrich voters are somewhat more in tune with Santorum as the nominee - but it's not all that big of an effect. In Ohio, for instance, 54 percent of Gingrich voters said they'd be satisfied with Santorum as the nominee. But 49 percent said they'd be satisfied with Romney.

Much of the argument seems to rest on the fact that Gingrich voters look more like Santorum voters demographically. That's so. Combining all of this year's exit poll (and entrance poll) results to date, more than six in 10 Gingrich and Santorum voters alike have been evangelicals; that drops to 38 percent of Romney's voters. And more than four in 10 of Gingrich and Santorum voters have been "very" conservative, dropping to 24 percent of Romney's.

Given their ideological makeup, moreover, almost two-thirds of Gingrich voters in Georgia, Ohio and Tennessee said Romney is "not conservative enough;" just 17 percent said he's "about right" ideologically. Santorum doubled Romney on "about right." On the other hand, a quarter of Gingrich voters in these states also said Santorum is too conservative, more than double Romney's number on that score.

Further, while many evangelicals may not prefer to vote for Romney, that doesn't mean they're ruling him out entirely. That's not the case in our national polls, and it wasn't the case in Virginia on Tuesday. There, given a choice only between Romney or Ron Paul, Romney's customary shortfall among evangelicals disappeared - he won 57 percent of non-evangelical voters in Virginia, but 62 percent of evangelicals as well.

Indeed, while Santorum is better-positioned demographically and ideologically for Gingrich's voters, that isn't the whole story. Gingrich voters to date, it turns out, have been particularly focused on electability and experience - 74 percent call one of these the most important attribute in a candidate, far greater than the share of Santorum voters who do so, just 34 percent.

Just 24 percent of Gingrich's voters prioritize "moral character" or being a "true conservative" - top attributes to 63 percent of Santorum's voters. Indeed Santorum is very strong, and Gingrich notably weak, on "moral character" - making Gingrich appear to be an unlikely choice for at least some Santorum voters.

The real answer, of course, is that candidates can't trade voters like baseball cards. Republicans who back Gingrich do so because he's persuaded them that he's their best choice. For Santorum, Romney or Paul to persuade them otherwise will depend, far more than anything, on the substance of their arguments.