However in this instance you were specific to name the tea party. In this present day the tea party as you referenced is a movement that was recently formed, not the original tea party. I just think it is interesting that you imagined the murderers in Boston could have come from a group that has no history of that at all, and lumped the tea party with other groups that have decades of experience with terrorism and murders.
To my knowledge the tea party never has committed a single terrorist act in the name of constitutional justification.
Yet it seems interesting that they are characterized by opponents, and even hoped to be that sort of group.