Personally, I could care less about Laura Ingraham. She's a Neocon and shouldn't be taken seriously about anything. As for the "insult", seriously? David Hogg and his followers lost their shit over that? What a bunch of snowflakes. I've had worst things said to me on the playground at school as a kid. Not getting into college is hardly the worst thing you can say about somebody. Get over it. If this kid really wants to be famous, he should learn that people are going to say bad things bout him. Some of them will be true. Some of them won't. That's part of the price you pay for being famous.
As for Hogg and his cult fanbase, I have a feeling it's going to end very badly for him. Somebody, somewhere is going to unearth some recording of him saying something racist, misogynistic, or anti-Semitic and then it'll be all over for him. It might even be a joke, but it won't matter. A lot of his followers strike me as people who don't like jokes. It's just something about him. People like him have way too much dirty laundry somebody is going to find something.