There is no doubt that the people we now revere in the USA as patriots who destroyed that cargo of tea as a protest against the taxes levied on it by the British Parliament were engaged in an act of defiance against lawfully constituted authority. But crucially — aren't they still teaching this in school? — "taxation without representation" was key to this protest. The American colonists had no say in setting the taxes being levied upon them. To me, this was valid protest. However, today, Americans have a representative form of government, and (for the most part; yes, I know about the District of Columbia) we are taxed by government entities for which we ourselves are responsible, as we voted for them. Therefore, invoking the "tea party" against taxes you personally dislike seems dishonest to me. If the mail-order/online sales tax law is passed by the government and signed by the president, it means that we have been taxed by a government that we elected, regardless of whether you voted for the individual members of that government or not.
Now, I suppose some of these tea-partiers are convinced that the current government is illegitimate in some way (presumably because Their Man Didn't Win). I have little patience with the conspiracy theorists. In general, with specific exceptions that need addressing, our government is elected by the citizens of the USA. (If you could vote but did not, you abstained, which means you said you'd agree with whatever decision the majority made.) That doesn't mean that every person is going to be completely satisfied with every government decision. (I certainly wish the Nevada government could see fit to subsidize rural transportation in Lyon County, for instance.) Anyone who thinks that "democracy" means "I always get exactly what I want," is being childish. Sometimes, our democratically-elected government does things that individuals don't want. Deal with it!
I guess if you're sufficiently ticked off, and are convinced the system has failed you completely and there's absolutely no redress through lawful means, you can go start a revolution. If you win, you were right; but until then, expect to be treated as traitors and rebels, just as the American revolutionaries were until they won. ("Rebellion is never unlawful in the first person, only the third person," to paraphrase Ben Franklin in 1776.) But I don't really see a real serious armed rebellion happening, gun-happy people and periodic crazies to the contrary. Even the US Civil War was waged by duly-elected-and-constituted state governments, albeit that one theory of Reconstruction stated that from the USA's point of view, those governments had committed suicide when they tried un-ratifying the US Constitution. Had it only been individual hot-heads, and had they not been able to get the local governments to back them, the War Between the States would never have happened.
I guess I'm just annoyed at the profoundly anti-government tone that so many people seem to take when the government does something they don't like. To restate Ronald Regan my way, Government is not necessarily the answer or the problem.