By Jonathan Zimmerman

Run, Chris, run!

For more than a year, GOP insiders have been urging New Jersey Gov. Christie to run for president. I'm not a Republican, and I disagree with most of Christie's political positions. But I still hope he throws his hat into the ring for one simple reason: Chris Christie is fat. And his nomination could strike a huge blow against one of our society's most vicious and enduring prejudices.

Numerous studies have demonstrated that fat people have a harder time finding work than others. They get smaller salaries and are less likely to be promoted than their thinner colleagues. They also have more trouble getting into college.

More women than men face this prejudice. In experiments with computer-generated images, viewers called women "overweight" after a 20 percent increase in size; men didn't get that label until their images grew by 35 percent.

It wasn't always this way. For most of human history, fat signified power and privilege. It was also considered sexy, as the nudes of Peter Paul Rubens and other Renaissance masters show.

Most of all, weight showed that you had made it in the world. "A fat bank account tends to make a fat man," the prominent physician George M. Beard wrote in 1879, touting the benefits of portly proportions. "Plumpness, roundness, size ... are rightly believed to indicate well-balanced health."

All this began to change around the turn of the 20th century, as urban Americans gained new access to a cornucopia of foods and other goods. At the same time, physical activity declined, thanks to transportation innovations and the decline of manual labor. Suddenly, middle-class Americans started to worry about going soft in the middle.

"An excess of flesh is to be looked upon as one of the most objectionable forms of disease," declared the Philadelphia Cook Book, which had sold more than 150,000 copies by 1914. Doctors got in on the act, too, warning that being overweight could harm the heart and other vital organs.

But Americans' real problem with fat was moral, not scientific. The growing consensus was that fat people had abandoned the virtues that had made the nation great: persistence, determination, discipline. No longer a token of hard work and success, fatness became a "character defect" and "evidence of lack of self control," as one observer noted in 1929.

The censure was always greater for females. Fat women were denounced as lazy burdens on their husbands, who did not have to meet the same exacting standards. Although Americans poked gentle fun at William Howard Taft's 300-pound heft, for example, they also voted him into the White House. "We don't care how much Mr. Taft weighs," one magazine declared after his election in 1908. "He is a good man and will make as fine a President ... as the country has ever seen."

But Taft also dropped 60 pounds with a pre-campaign diet, reflecting changing expectations about men as well. That shift picked up steam after World War II, when fatness began to inhibit male opportunities and earnings. "In love or business, the man with a paunch loses his punch," said the 1971 book Secrets for Staying Thin. By the 1990s, humorists were eagerly skewering Bill Clinton's eating habits.

Today, of course, we often justify anti-fat prejudice on health grounds. And, surely, excess weight is associated with diabetes and a host of other ailments. But it's simply false - and deeply prejudicial - to claim that all fat people are unhealthy.

According to a 2008 report in the Archives of Internal Medicine, half of those who are overweight and a third of those who are obese have healthy blood pressure and cholesterol levels. In 2007, the Centers for Disease Control and Prevention found that overweight people have longer life expectancies than those of average weight.

For his part, Christie has acknowledged his lifelong struggle to control his weight. And to his credit, he recently endorsed first lady Michelle Obama's campaign to improve youth nutrition and fitness. So did former Arkansas Gov. Mike Huckabee, who dropped 110 pounds before his 2008 presidential run.

Huckabee recently took himself out of contention for the 2012 GOP nomination - amid reports, as it turns out, that his weight was once again on the rise. So did Haley Barbour, the generously sized Mississippi governor.

That leaves Christie, whose presidential campaign would remind millions of Americans that fat people can lead healthy, productive, successful lives. I hope he runs and wins the nomination to challenge the famously svelte President Obama. And may the best man - not the thinnest - win.

Jonathan Zimmerman teaches history at New York University and lives in Narberth. He is the author of "Small Wonder: The Little Red Schoolhouse in History and Memory" (Yale University Press). He can be reached at jlzimm@aol.com.