I may draw some flack for asking this, but I think this question bears asking. Do you think these tea parties are biblical and have the spirit of Christ behind them?
There is a major difference between our times and then. Rome was an occupying force in Judea. They ruled with an oppressive military hand. You didn't protest their occupation unless you wanted to lose your head. Thankfully, we live in a country where this is not the case, and indeed, our very founding documents encourage us to publicly air our grievances with the government in a civil and peaceful manner.
We can do such, and still render unto Caesar the things that are Caesar's. If you are in the position to do so, do you not express concerns about how to better run whatever company you may work for? If you are involved in a local club of some sort, do you not express concerns about how to better run the organization?
If we can express our grievances in these contexts, then why not express them in a government such as ours? After all, our government is "by the people, for the people, and of the people." Our elected officials need our feedback on a regular basis, and not simply on election day. If they "represent" us, then we need to express what we think on a given issue so that they can vote accordingly.
These things are not contrary to kingdom principles. It's simply part of being "in the world." Though, we must never be of it.