IT’S JUST THE GOPe’S LATEST DELUSION: Sahil Kapur at Bloomberg examines “Four Problems With the ‘Winnowing’ Theory of Trump’s Downfall.

Jeb Bush’s decision to drop out of the presidential race after a dismal fourth-place finish in South Carolina sped up a process that Republican elites have long been praying for: a winnowing of the field that could thwart the candidacy of Donald Trump.

The theory is that Trump, who notched his second consecutive primary victory on Saturday, is a factional candidate with a “hard ceiling” of support limited to the one-third of the party. . . .

Trump, however, bristled at that argument during his victory speech Saturday night.

 “A number of the pundits said, ‘Well, if a couple of the other candidates dropped out, if you add their scores together it’s going to equal Trump,'” he said in a mocking tone. “But these geniuses—they don’t understand that as people drop out I’m going to get a lot of those votes also. You don’t just add them together.”

Trump has a point, and a close examination of Republican voter data shows that the “winnowing” theory has four serious flaws.

1. It’s unclear Trump loses a three-person race

An Economist/YouGov national survey released last week tested the theory that Trump would suffer in a three-person race with his two chief rivals. It found Trump winning with 46 percent of the vote, ahead of Marco Rubio with 28 percent and Ted Cruz with 26 percent. . . .

2. Trump’s ‘hard ceiling’ is overrated

. . . . One way to test this, pollsters say, is to gauge what percentage of voters could see themselves supporting a candidate.

The January NBC/Wall Street Journal survey found that 65 percent of likely Republican voters could see themselves supporting Trump, a staggering jump from the 23 percent of voters who did last March, before he announced his presidential run. Cruz and Rubio fared modestly better, at 71 percent and 67 percent, respectively.

“The longer Donald Trump stays in the race, the more likely GOP voters are willing to vote for him,” Republican pollster Frank Luntz tweeted in response to that statistic.

By contrast, in January 2012, 59 percent of Republicans saw Romney, who went on to win the nomination, as “acceptable,” according to Gallup.

3. Trump’s support is broad-based in the party

While Rubio pitches himself as best-positioned to unite the party, Trump has a case of his own to make. Exit polls in the first three states show strong support for the New York billionaire across age groups, sexes, ideologies, income level, religious inclinations, issue preferences and candidate qualities.

Though he lost some subgroups in South Carolina—like well-educated voters, who Rubio won, and very conservative voters, who Cruz won—exit polls showed no glaring vulnerability that could undermine him. The only GOP faction that overwhelmingly views Trump as unacceptable is national party leaders and senior operatives, whose influence is diminished by the fact that they are loathed by the GOP base (a dynamic that helped give rise to Trump in the first place). . . .

4. ‘Second choice’ votes aren’t all anti-Trump

While a crowded field arguably helps Trump more than a small field, a NBC/SurveyMonkey poll released Thursday indicates that supporters of other candidates would not unify against Trump as others drop out.

The survey found that Bush backers are torn between Rubio (19 percent), John Kasich (16 percent), Cruz (12 percent) and Trump (11 percent). Kasich fans are torn between Rubio (24 percent), Trump (16 percent) and Cruz (10 percent). Ben Carson supporters split between Cruz (24 percent), Trump (22 percent) and Rubio (16 percent). . . .

Trump’s “unfavorable” ratings are not as high as many of the establishment pundits incessantly suggest. A February 10-15 Quinnipiac poll among registered voters (MOE +/- 2.7 percent) found that among Republicans and Republican-leaning Independents, Trump’s favorable rating was 62 percent, with unfavorables of 31 percent (the other 7 percent didn’t know one way or the other).

Cruz’s favorable/unfavorable rating, by contrast, was 62/23 (with 15 percent unable to say); Rubio’s favorable/unfavorable was 64/17 (with 19 percent unable to say).

One thing that is striking about the favorability numbers is that Trump’s fame translates into most Americans having an opinion of him, one way or the other (with only 7 percent not yet having formed an opinion). Cruz and Rubio, by contrast, have relatively large percentages of the public–more than two times as many–who have not yet formed an opinion about favorability (15 and 19 percent, respectively). This naturally makes the “unfavorable” ratings of Cruz and Rubio appear markedly smaller. The “favorability” ratings of all three candidates among Republicans, however, is remarkably similar, with 62 percent for Trump, 62 percent for Cruz, and 64 percent for Rubio–a virtual dead heat.

Trump’s favorability numbers among Republicans are very similar to Romney’s in February 2012 (65/28 among Republicans; not including Independents) and Trump’s favorability among Independents seems to be notably higher. Specifically, the Quinnipiac poll has Trump with a 62/29 favorability rating among Independents, whereas the February 2012 Gallup poll had Romney at 37/44 favorability among Independents. Romney’s low favorability ratings improved significantly after he became the presumptive nominee of the Republican party, a typical phenomenon that would presumably happen to Trump (or Cruz or Rubio) as well. Moreover, there is some evidence that Trump enjoys the support of around 20 percent of likely Democratic voters in a general election.

I’m not sure how accurate any of these polls are, but if one is going to attempt to rely upon them to prognosticate, the story being told about Trump’s favorability ratings leading to “unelectability” seems both exaggerated and incomplete.

RELATED: Trump’s lead grows with Jeb out of the race.