"He says that he wants his act of violence to initiate change - I assume in the IRS specifically, but also in American politics in general. That's the definition of terrorism."
Tell that to Thomas Jefferson and George Washington...
Terrorism is a strategy not a sin, just because you happen to agree with what they are saying does not mean they are not terrorist's. Also you don't need actually kill people to induce fear, setting fire to an empty building can also count.
I agree in principle, but that's not how society defines it. By popular definition, a terrorist is someone who commits atrocities for a cause that one does not agree with. If there was agreement, they'd be labeled a "freedom fighter" or something like that.
Tell that to Thomas Jefferson and George Washington...