Mitt Romney would like the story of Seamus the dog's wild rooftop car ride to go away, but clearly, that's not going to happen. In 1983, the Romney clan took a 12-hour car trip to the family lake house in Canada, with their Irish setter Seamus riding in a specially outfitted dog carrier strapped to the roof of the station wagon. At one point, the terrified Seamus emptied his bowels down the car's back window, at which point Mitt pulled over, calmly hosed down the car and the dog, and drove on — with Seamus back on the roof. Good story? Sure. But ever since son Tagg shared the family anecdote with The Boston Globe in 2007, pundits, animal-rights activists, comedians, and political rivals have, sometimes obsessively, kept the story alive and kicking. Why aren't people letting this nearly 30-year-old tale fade away? Here, four theories:

1. It's a window into Romney's all-business attitude
The Seamus story perfectly encapsulates the character of a rigidly efficient man who won't let a sick dog derail his meticulous plan for driving 12 hours with just a single fuel stop, New York Times columnist Gail Collins tells NPR. "It absolutely fascinates me," adds Collins, who has mentioned the Seamus story at least 50 times in her columns. GOP rival Rick Santorum also claims that the Seamus anecdote raises important "issues of character," and his aides are even more direct. "Quite frankly, I'm not sure I'm going to listen to the value judgment of a guy who strapped his dog to the top of the roof of his car and went hurling down the highway," Santorum adviser John Brabender told CNN on March 14.

2. And it highlights Romney's awkward strangeness
Ever since the story surfaced, people have "scrunched their noses and said, 'What?'" former Romney Iowa campaign chairman Douglas Gross tells The Washington Post. It's like Romney's recent comments that Michigan's trees are just the "right height," says Gross. It's just "one of those things about Mitt that seems otherworldly. It seems abnormal and raises questions about who he is and whether he's one of us."

3. Seamus has become a proxy for Mormonism
The dog-on-the-roof tale is only half of a "problematic palindrome" for Romney: "Dog/God," says Brad Hirschfield in The Washington Post. We Americans "like to see ourselves in our candidates," and people who think Romney is somehow different feel more comfortable criticizing him for his odd pet treatment than his Mormon faith, which some Christians have bizarrely singled out as a troublingly foreign religious tradition. I, for one, endorse "an end to using irrelevant pet stories and unfounded fear of someone else's faith as a substitute for the serious debate we need" about the future of America.

4. Americans simply love their dogs
The obvious reason this "darn story just won't go away" is that "Americans love their dogs," says Catherine Poe in The Washington Times. And for a country that demands its White House occupants have a pooch, the image of Romney's "very sick dog splattering the car with its illness" is a very big negative. In "one dog lover's opinion," says Lanny Davis at Fox News, "anyone who puts his dog in a cage on top of a car for a 12-hour drive and then deludes himself or tries to delude others that the dog really enjoyed it... shouldn't be president of the United States." Cruelty to dogs "is the ultimate Purple Issue," something red states and blue states can agree to abhor, and the more people learn about Romney's "heartless" treatment of Seamus, the fewer votes he'll get.