By Richard Cohen - July 7, 2009

In his novel "The Plot Against America," Philip Roth imagined that Charles Lindbergh, an isolationist and an anti-Semite (but a hell of a flyer), ran for president in 1940 and beat Franklin Roosevelt. In his novel "Fatherland," Robert Harris imagined a Britain that had succumbed to the Nazis. These works are categorized as "alternate history." Here is my contribution to the genre: Sarah Palin becomes president of the United States.

Far-fetched? Not really. After all, Palin really was on the Republican ticket, and the Democratic candidate was both untested nationally and the first African-American to claim the nomination. A significant misstep here or there and the winner could have been John McCain, the oldest man ever elected president.

My brothers and sisters in punditry spent a jolly Fourth of July weekend having a swell time with Palin and her decision to quit as governor of Alaska. Her words were parsed for their meaning and her plans were deduced while political operatives of both parties analyzed her move to see if she is really very clever or as dumb as a mud wall. A good time was had by all.

It would behoove us, though, to consider how close we all came to utter disaster -- the "counterfactual" suggested above. A recent Vanity Fair article provides further evidence of just how awful a vice president (or president) Palin would have made. During the campaign, she proved allergic to briefings and remained determined to stay uncorrupted by knowledge. More recently, she explained her decision to -- permit me some GOP talk -- cut and run as Alaska governor by lapsing into no known language, explaining herself afterward in a burst of Tweets that only raised more questions. One question, though, has been settled: She is unfit for office.

What is most pertinent about Palin is that she was named to the GOP ticket -- a top-down choice by McCain. This was the most reckless decision any national politician has made in the longest time, and while it certainly says something about McCain, it says even more about his party. It's lost its mind.

Recall, after all, that Palin was not McCain's first choice. That was either Joe Lieberman or Tom Ridge. They were both rejected by the party itself because of their appalling moderation on social issues over which the president has little direct authority anyway -- abortion, above all -- and in Lieberman's case because he had been a Democrat. In desperation, McCain turned to Palin.

Was there a scream of protest? No. Did the Republican Party demand to know of McCain what the hell he had done? Again, no. Was it OK with the GOP if the person a heartbeat away from the presidency was -- pardon me, but it's true -- a ditz with no national experience whatsoever? You betcha. The party had cracked up, accepting a nullity because she was anti-abortion over a seasoned senator and former governor because they were not. Ideology won. The nation lost.

Almost as interesting as Palin is South Carolina Gov. Mark Sanford. Never mind his affair. These things happen. Concentrate instead on how he hid his affair -- by disappearing and calling attention to himself. Note also that even before he somehow took the Appalachian Trail to Buenos Aires, he was renowned for rejecting federal stimulus money. Before that, as a congressman, he claimed to have forsaken a housing allowance -- and a cot -- and said, "I sleep on the floor of my office." Most of us would consider this weird behavior. In the GOP, it was seen as presidential timber.

Shall I go on? Newt Gingrich, another possible candidate, is the Old Faithful of the Grand Old Party, erupting on a regular basis. He recently suggested that Judge Sonia Sotomayor is a racist because of her comment about the innate astuteness of a "wise Latina." He later apologized, but his hair trigger is well established. This is the same Gingrich, you may recall, who threw a tantrum in 1995 when President Clinton seated him in the rear of Air Force One and then, with ingenious malice aforethought, failed to come back to chat. As for the rest of the GOP candidates, all of them must be vetted by the party's Grand Inquisitor, Rush Limbaugh, a belch from the gutter.

For Tina Fey, Sarah Palin was comedic material. For the rest of us, she's been a summer weekend's diversion. But when the chuckling is over, you have to ask yourself what in the world was she doing on the GOP ticket and what would have happened if McCain had won? Only part of this is alternate history. The rest is frightening reality.