Just because a political maxim has been repeated ad nauseam for more than 20 years doesn’t make it so.

Contrary to the two-decade-old insistence of the Bushioisie — GOP uberlobbyist Haley Barbour’s Sunday appearance on CNN’s “State of the Union” being only the latest example — Ross Perot did not “cost” George H.W. Bush his 1992 reelection; rather, Perot’s campaign saved George H.W. Bush from an ignominious and humiliating loss, a defeat that likely would have rivaled Franklin Roosevelt’s 1932 drubbing of Herbert Hoover.

Consider:

On November 3, 1992, Bill Clinton defeated George H.W. Bush and Ross Perot for the presidency by a margin of 43-37-19 percent.

Ever since that loss to Bill Clinton, it has been the standard operating procedure of Bush supporters everywhere to blame the loss on Perot’s independent run, and the 19 percent of the electorate he won that November — “a majority of those voters would probably have gone Republican in a two-party race,” wrote Bush’s vice president, Dan Quayle, in this Washington Post piece from April, 2010, before concluding, “Speaking on behalf of the Bush-Quayle campaign, to this day we firmly believe that Perot cost the Republican Party the White House.”

Barbour replayed this canard as recently as Sunday’s episode of CNN’s “State of the Union,” when, commenting on the possibility of an independent run by Donald Trump, Barbour said, “But the big question for me is, most important question, will Donald Trump say to the Republican audience, I will not run as a third party candidate. I will not run as an independent. I understand what happened in 1992, that Ross Perot gave the Clintons the White House.”

First, Perot’s campaign was not the cause of the malady that afflicted the 1992 Bush-Quayle campaign, it was but a symptom. Perot didn’t even appear on Larry King’s CNN show declaring that he would consider running (if the American people put him on 50 state ballots!) until February 20, two days after Pat Buchanan had scared the bejeebers out of the Bush operation by holding Bush to just 53 percent of the vote in the New Hampshire primary.

Second, the polling data at the time simply does not support the contention that Perot’s 19 percent of the vote came largely out of Bush’s hide. In fact, it shows just the opposite.

The 1992 Battleground Survey — conducted and analyzed on a bipartisan basis by The Tarrance Group (a fabled GOP firm) and Lake Research Partners (a storied Democratic firm) — shows the following:

On September 30 — the last day before Perot re-entered the race — Clinton led Bush by an 11-point margin, at 49-38 percent, with Perot taking six percent.

One day later — the day Perot re-entered the race — Clinton’s lead shrank to nine points, 47-38 percent, with Perot nudging up a point to seven percent.

Thirty days later, on November 1 — the last day the survey was fielded — Clinton’s lead had shrunk further, to just four points, at 40-36 percent over Bush, with Perot polling at 19 percent.

So, during the course of Perot’s late-season charge, Clinton’s support dropped from 49 percent to 40 percent (a significant nine-point drop), while Bush’s support dropped from 38 percent to 36 percent (a mere two-point drop, inside the margin of error of the survey).

Meanwhile, Perot was gaining 13 points on the ballot — nine points of which came from Clinton, two points of which came from Bush, and two points of which came from previously undecided voters.

In other words, to the extent voters left Bush and Clinton for Perot, those who left Clinton for Perot outnumbered those who left Bush for Perot by more than 4-to-1.

Worse for the Barbour/Quayle argument, the remaining five percent of voters who remained undecided right up until the election split 3-1-1 for Clinton-Bush-Perot on Election Day. That’s another way of saying that on the day before the election, 80 percent of the remaining undecided voters had, in fact, decided — they had decided they were not going to vote for Bush. They just hadn’t decided whether they would ultimately cast their vote for Clinton, or for Perot. And Clinton ended up getting 75 percent of them.

Do the math. Had Perot not been in the race, Clinton’s final tally likely would have been 13 points higher than it was, while Bush’s likely would have been just three points higher.

Without Perot in the race, the final outcome likely would have been 56-40 percent, Clinton over Bush. That would have been the worst loss by a Republican President seeking reelection since 1932, when Franklin Roosevelt crushed Herbert Hoover by a 57-40 percent margin.

So, can we put this shibboleth to rest, once and for all?