Ann Coulter is a plagerist.
Possibly she is, but those quotes don't prove it. It takes more than a sentence here or there to constitute plagiarism. Since she read the work from which the original sentences came, it seems likely that some turns of phrase just stuck in the back of her head. Perhaps when they came back to her, she had no idea that she was remembering them and not composing them. This has happened to me, and it's embarassing enough when I'm the one who catches it.
Another possibility is that both are taking their phrasing (in these two instances) from an original source they used in common.