In James Thurber’s Further Fables for Our Time, he writes the tale of “The Peacelike Mongoose.”

In cobra country a mongoose was born one day who didn't want to fight cobras or anything else. The word spread from mongoose to mongoose that there was a mongoose who didn't want to fight cobras. If he didn't want to fight anything else, it was his own business, but it was the duty of every mongoose to kill cobras or be killed by cobras.

""Why?" asked the peacelike mongoose, and the word went around that the strange new mongoose was not only pro-cobra and anti-mongoose but intellectually curious and against the ideals and traditions of mongoosism.

"He is crazy," cried the young mongoose's father.

"He is sick," said his mother.

"He is a coward," shouted his brothers.

"He is a mongoosexual," whispered his sisters.

Strangers who had never laid eyes on the peacelike mongoose remembered that they had seen him crawling on his stomach, or trying on cobra hoods, or plotting the violent overthrow of Mongoosia.

"I am trying to use reason and intelligence," said the strange new mongoose.

"Reason is six-sevenths of treason," said one of his neighbors.

"Intelligence is what the enemy uses," said another.

Finally, the rumor spread that the mongoose had venom in his sting, like a cobra, and he was tried, convicted by a show of paws, and condemned to banishment.

Moral: Ashes to ashes, and clay to clay, if the enemy doesn't get you your own folks may.

This fable was written denouncing the McCarthyist paranoia that led to the blacklisting of fellow American citizens out of suspicion that they may be communist sympathizers, but the message of this tale extends well beyond the Red Scare. Today, we see that “maverick” (or, perhaps, “mongoose”) politicians who do not vote the party line are often ostracized as “black sheep” and attacked by their own folks, as Thurber suggests.

Consider Democrats’ reactions to Sen. Joe Lieberman (I-CT) running for office as an Independent after losing the Democratic Primary. Former Clinton adviser Paul Begala nicknamed him “Traitor Joe,” journalist Ari Berman described him as a “back stabber,” and television show host Rachel Maddow proclaimed him to be a “wrench in the works.” On the other side of the aisle, though, Republicans celebrated Lieberman as “a really exceptional senator” and “a national treasure.” Conservative pundits Rush Limbaugh, Sean Hannity, and Glenn Beck all supported his candidacy for the U.S. Senate. Similarly, consider Republicans’ reactions to Sen. Olympia Snowe (R-ME) after she voted in favor of the 2009 stimulus package and the Senate Finance Committee’s healthcare reform bill. Republicans lambasted her as one of three then-Republican Senators who did not vote the party line as the “Traitor Trio”. At the same time, Democrats heralded Snowe for her willingness to compromise and leadership in doing what is best for the country.

Social psychologist Pete Ditto and graduate student Andrew Mastronarde published experimental evidence supporting this phenomenon in the Journal of Experimental Social Psychology. Across three studies, they found that although participants generally liked the idea of a political maverick, participants viewed mavericks of their own party more negatively than their party-line counterparts. Perhaps this is part of the reason that the long-self-pronounced political maverick Sen. John McCain (R-AZ) is now renouncing the idea that he ever was a maverick.

From ashes to ashes, and clay to clay, if the other party doesn’t get you, extremists within your own party may.

— Matt Motyl