At the absolute minimum, for a tax to be justified it needs to go towards something that is authorized in the constitution.
I prefere to say that taxes only to pay for police, courts, and defense are justified, which is even less than the constitution authorizes. But I'm willing to start with "In the constitution."
Since our taxes pay for all kinds of unconstitutional crap, government is the thief for doing it. So I would absolutely vote "Not guilty" if I were on a jury for someone being charged with tax evasion.