Republican presidential candidates Rick Santorum, left, and Mitt Romney, center, are the two tallest candidates left in the GOP primaries. Newt Gingrich, right, and Ron Paul fall short. (Charles Dharapak/AP)

Everyone but me was surprised that former senator Rick Santorum swept three GOP contests last Tuesday. Since 1988 I have been writing in Style about our abject failure to see the real basis of almost all our electoral decisions, of which Santorum’s victories are a prime example.

We subject newspaper readers and television viewers to months of senseless babble about economic trends, political fundraising, campaign ads and debate strategies. If we just spent a few seconds with each candidate and a tape measure, the results would be obvious.

Santorum is 6-foot-2, taller than any of the GOP presidential candidates except former Massachusetts governor Mitt Romney, who is the same height. Those few inches make a difference. They explain 11 of the 15 presidential election outcomes of the television era, beginning in 1952, including John F. Kennedy’s upset of Richard Nixon, the rise of Ronald Reagan and Barack Obama’s historic win in 2008.

This primary season is just another contest between the two tallest guys. The others have little chance. Former House speaker Newt Gingrich and Rep. Ron Paul are just 6 feet tall. When the candidates line up at the beginning of each debate, you can tell Santorum and Romney are taller. Candidates quitting the race have likewise been shorter than the latter two — former Utah governor Jon Huntsman is 6-0, businessman Herman Cain and Texas Gov. Rick Perry are both 6-1, and Rep. Michele Bachmann is 5-2.

Yet I am ridiculed for reporting this. When I call and ask for the candidate’s height, the first response is, “What?” When I repeat the question, they say, “Are you sure you’re from The Washington Post?” Sometimes they giggle, then hang up. I have to call back often.

I do not want to insult The Post’s splendid political reporters, many of them friends, but they also ignore this. Every four years I save The Post from disgrace by writing a piece on the issue, but it’s difficult to keep it up with so much resistance.

The rest of the political press doesn’t do any better. Search for the word “height” on Politico’s Web site, and all you get are irrelevant references to President Obama calling the nation’s wealth gap “the height of unfairness” or somebody’s new stance being “the height of irresponsibility.”

I am sensitive to this because I am 5-foot-4, down from my lifetime peak of 5-foot-6 (okay, 5-foot-53 / 4ths). I have long thought that my below-average stature diminished my prospects. Social scientists agree. Humans are biased in favor of taller people. Height has long been a marker of power. Before our species developed firearms, bigger people tended to win most fights, so we got in the habit of letting them make the decisions. If we were an insectlike race in which adults were smaller than larvae, we might not associate size with maturity and leadership, but what can you do?

Whatever the polls say, Santorum or Romney will be nominated, and in a general election against either of them, Obama, at 6-1, will be in trouble.

He has a chance. George W. Bush defied the odds by beating a taller candidate, John Kerry, in 2004. (Al Gore in 2000 was also taller than Bush but . . . well, no use getting started on that.)

Obama hasn’t helped himself. He appears in photos with his wife and older daughter, who are unusually tall and make him appear smaller than he is. This time he won’t have the four-inch advantage he had over McCain.

It would be nice if this distressing bias were at least discussed on the campaign trail. Maybe if we confronted it, it would lose some of its influence. But don’t count on it.

And don’t be surprised if footwear consultants are spied going in the back door of some campaign headquarters. There are ways to add an inch or two.