Perhaps they figure Americans are ready to be shown how their 'public servants' really think of them. Perhaps they tire of the dance around the constitution they've had to do to not push enough Americans over the edge. Perhaps they figure they cannot get anymore out of us without combat. Perhaps we are to be provoked.
That's one line of thinking. Another would be that perhaps a few puppetmasters are just done toying with us and are now going to smash all their toys-us-and get their global plantation, and that their useful idiots are going to push America into civil war, while China exploits the situation to go imperial.
Whatever the case, we know reasoning with these people is like busting your head up against a brick wall. Prepare.