The narrow primary defeat of veteran Sen. Joe Lieberman in Connecticut's Democratic primary is more than a loss for one man. It is a loss for his party and for the country. It completes the capture of the Democratic Party by its Taliban wing.

They used to be "San Francisco Democrats," a phrase coined by former U.S. Ambassador to the United Nations Jeane Kirkpatrick to describe the party's 1984 convention. But they have now morphed into Taliban Democrats because they are willing to "kill" one of their own, if he does not conform to the narrow and rigid agenda of the party's kook fringe.

Mr. Lieberman's one "sin," in the eyes of the Taliban Democrats, was that he supported the effort to defeat the insurgent-terrorists in Iraq. As a Jew, Mr. Lieberman is particularly sensitive to those who have targeted the Jewish people for extinction. But even if he weren't Jewish, he would still "get it," because he understands what's at stake in the region and has correctly concluded that the consequences of American failure in Iraq would be catastrophic.

His detractors, who brought him down in the primary with a one-issue, inexperienced and unqualified candidate, Ned Lamont, hate President Bush so much that their judgment has been distorted. Former Bill Clinton aide Lanny Davis, in a recent column for the Wall Street Journal titled "Liberal McCarthyism," printed a sample of the incendiary rhetoric directed toward Mr. Lieberman. There is thinly-veiled anti-Semitism ("As everybody knows, Jews only care about the welfare of other Jews...." Posted on Daily Kos); irrationality ("Joe Lieberman is a racist and a religious bigot." Daily Kos); and personal attack ("Lieberman cannot escape the religious bond he represents. Hell, his wife's name is Haggadah or Muffeletta or Diaspora or something you eat at Passover." Posted on the Huffington Post blog).

It didn't matter that Mr. Lieberman, whose wife's name, by the way, is Hadassah, ran as the vice presidential candidate with Al Gore in 2000, or that he has voted against most of President Bush's domestic agenda. The Taliban wing of the Democratic Party cannot countenance any "heretics" who do not toe their line.

Though Mr. Lieberman says he will run as an independent, the damage has been done. It will be difficult for any Democrat to seek consensus with any Republican without being targeted as an infidel worthy of electoral death. Our already-poisoned political dialogue has not only been made more toxic, but contagious. Taliban Democrats have effectively issued a political "fatwa" that warns all Democrats not to deviate from their narrow line, or else face the end of their careers through a political jihad. Perhaps the few remaining rational Democrats should put on their burkas now and submit to the will of the party mullahs.

What is wrong with Democrats? Can't they see that when the face of their party belongs to ultra-leftists like George McGovern, Michael Dukakis and John Kerry, they lose? For those who still believe not only in a strong two-party system, but also in compromise and conciliation in order to promote the general welfare and seek the common good, the Lieberman defeat strikes an especially harmful blow.

At the height of social conservative power in the Republican Party, pro-choicers and pro-gay rights officials like Mayor Rudy Giuliani of New York City and California Gov. Arnold Schwarzenegger were featured speakers at GOP conventions. Republican officials described their party as a "big tent" with room for everybody.

Mr. Lieberman's loss reduces the size of the Democrats' tent to that of a pup tent. The message it sends is that only those who conform to the left-wing fundamentalist worldview will be allowed in. Is that a message Democrats want to take into future campaigns? Do they wish to pervert John F. Kennedy's vision and instead say that the United States will pay no price, bear no burden and go nowhere in the defense of liberty?

If that is the message the Taliban Democrats want to send to the nation, they have all but guaranteed a Republican presidential victory in 2008 and GOP losses, if any, might not be as bad as predicted this November. Karl Rove could not have devised a more brilliant plan. But Joe Lieberman deserves better.

Cal Thomas is a nationally syndicated columnist.

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