Kicked out of the state? Would that be before or after being "burned at the stake as a traitor"? This seems a tad extreme for presenting less-than-rabidly-pro-war sentiments. This is America, where we have the freedom to express our opinions, no matter how unpopular they might be. One shouldn't even be fired for such an "offense," let alone "deported" to another state or executed by torturous means already outlawed by our own Constitution.
However, *IF* the kid's representation of the situation is essentially factually correct, I think he might have a bit of a point (besides the one on his head) concerning the fact that teachers should not use a classroom as a bully pulpit for airing political views; it's not nearly as heinous as spouting religious dogma, but a teacher really should at least try to be neutral in presenting this stuff.
But don't get me wrong; I think it's quite possible that the teacher did nothing particularly political beyond making this one accidentally truncated comment, and this kid read reams of socialist diatribe into it out of thin air. A valid point in the abstract does not mean a valid point in the particular circumstance. And in any case, even if the guy was passing out The Communist Manifesto, this kid is overreacting in a HUGE way.