Probably in response to this or this, Spencer Ackerman asks:

Can someone explain to me why the term "Democrat Party" is a slur? I recognize that it sounds grating, and agree that it's probably intended to be demeaning. But... why should it be? Help.

I think part of our hard-wiring for language has to do with understanding the concept of names, feeling ownership of our names, and feeling unsettled if our names are mangled in a way that seems thoughtless or intentional. Someone -- David Halberstam? Robert Caro? -- has written that LBJ, a master political game-player, regularly mangled people's names; surely that threw those people off stride in a way that worked to LBJ's advantage.

I think "Democrat Party" taps into the hard-wired response to one's own name. It's our group name, and we know it's being mangled deliberately. It's unsettling on a basic level of language.

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Well, here's NBC's John Chancellor on LBJ:

One thing Lyndon Johnson did that I always thought was marvelously colorful was that he would mispronounce people's names deliberately. I've seen him do that, and I've seen him do it to people, to put them off their guard. I've seen him do it to government people.

That's the trick. "Democrat Party" is a variation.