The Texas Election Code prohibits "electioneer[ing] for or against any candidate, measure, or political party".
The Tea Party isn't a political party, but they do advocate voting for or against specific candidates or measure.
Sorry, but this is "beating a dead horse". Leave all political statements of any kind in the car when you go to vote.
Can you wear an American flag?
That flag is NOT the flag of any political party or candidate.
She should be free to wear it.
Go arrest the Wookie for actual violations of the law.