Entrepreneur Donald Trump dismissed the surging candidacy of Rick Santorum by claiming that Santorum lost his Senate seat in 2006 by a wider margin than any incumbent senator in history. He’s wrong.

In fact, there have been two dozen incumbent senators who have taken worse beatings than Santorum did in 2006. Trump need only have checked back as far as the 2010 midterm elections — when Democrat Blanche Lincoln lost her Arkansas seat — to find an incumbent senator who lost by a bigger margin than Santorum did.

Trump, who flirted for months with a presidential run, announced his endorsement of Mitt Romney on Feb. 2. A week later, Trump opined on CNN about Santorum, who the night before had pulled off a clean sweep of caucuses and non-binding primaries in Colorado, Minnesota and Missouri.

Trump, Feb. 8: Rick Santorum was a sitting senator who in reelection lost by 19 points, to my knowledge, the most in the history of this country for sitting senator to lose by 19 points. It’s unheard of. Then he goes out and says, oh OK, I just lost by the biggest margin in history now I’m going to run for president. Tell me, how does that work? How does that work?

With electability ranking as a high priority for Republican primary voters, Trump’s statistic is more than just cocktail party trivia. But he’s way off.

We came across some research on this very subject done by Joe Lenski, executive vice president of Edison Research, a market research and exit polling firm based in Somerville, N.J.

Using data from America Votes and Congressional Quarterly’s Guide to U.S. Elections, Lenski compiled a list of the worst drubbings ever absorbed by incumbent senators. Topping the list is Jacob Javits. Despite winning four terms in the Senate as a Republican, Javits lost in the 1980 Republican primary to Alfonse D’Amato. Javits then ran in the general election as a Liberal Party candidate, vainly trying to retain his seat. But he finished third in the race, 33.8 points behind the winner, D’Amato.

So where does Santorum fall on the list? Santorum — who in 2006 lost a reelection bid to Democrat Bob Casey Jr. by 17.4 points — is 24th. And that was before incumbent Democrat Blanche Lincoln lost her Senate seat in 2010 by 21 points.

Lenski noted in his Aug. 27, 2010, research that only 29 senators had lost by as wide a margin as 17 percentage points in 48 election cycles covering more than 1,000 reelection bids (less than 3 percent).

“When incumbent senators lose they usually lose by small margins,” Lenski wrote. “And with the advent of modern polling, when they realize they are heading for a big loss they tend to withdraw from the race first. That is probably why the only recent name on the list is Rick Santorum in 2006.”

It was a big loss for Santorum, Lenski told us by phone. But as is often the case, he said, when people use superlatives — as Trump did — “it is not 100 percent accurate.”

Speaking of which, Republican rival Newt Gingrich has several times made a similar claim, saying Santorum “lost Pennsylvania by the largest margin of any senator in the history of the state.” But even by limiting the claim to Pennsylvania senators, Gingrich is wrong.

Incumbent Sen. Joe Guffey, a Democrat from Pittsburgh, Pa., was soundly defeated in 1946 by Gov. Edward Martin, by a margin of 19.4 points. That ranks as the worst showing by a senate incumbent in Pennsylvania history.

When asked on CNN to react to Trump’s quote later in the day, Santorum wisely refrained from saying that his was only the 25th worst loss by an incumbent senator. Instead, he offered this comeback:

“Why don’t you ask Abraham Lincoln, who lost just about every single race he ran before he ran for president?” Santorum said. “A lot of folks lose races, but I didn’t lose, unlike Governor Romney, is my principles. I stood up and fought for what I believed in, in a very tough election year.”

Santorum, we should note, has himself not been immune to a bit of revisionism with regard to the topic of defeating incumbents. In August 2011, when Santorum claimed he “defeated three Democratic incumbents,” we pointed out that he defeated two incumbents; in two other congressional elections, he was the incumbent.

— Robert Farley