Patriot Act repeals part of Posse Commitatus I belive. Army can be used if certain criteria are met. This might be such a time.
I don't care who suppresses these people, personally. But it's probably not the US military, because otherwise things would be in better shape. One of the big problems with this is that the Governor was slow to ask for any Federal aid, and while I am not a big advocate of the Feds, sometimes they're the only people who can deal with a situation of a certain magnitude. And this one qualifies - and I'd like to think my insanely high tax rate is at least buying something for somebody in this country.