Coulter has made a career of pushing the envelop as far as she can. As a result, she sometimes says important things that no one else dare say. And sometimes she says crazy stuff.
Coulter's public persona is an act. She's playing a character to sell books, or whatever she is shilling these days.
This stunt is calculated, and it coming the same time as Don Lemon saying his stupid thing about Haley makes me suspect there's a campaign being coordinated here. Practically nobody would be able to keep Haley's name in the news without a controversey to talk about, and Poof! Two villains appear and say controversial and stupid things for Nikki to "rise above".