You are still confused between individuals and the State. A robber acts in the knowledge that he is breaking the law and going against the society he is preying upon. A democratic state acts on behalf of its citizens, it acts within the law and tax is an agreed part of the system.
The "STATE" is a group of individuals elected by voters, a coup de'tat, or a succession of "royal blood". It's likely that they may not even represent a majority as this is rare, even today. At best, a democratic state should only legally act on behalf of only those voters who expressly gave their consent.
If I haven't contracted for services, or at the very least voted for you and your "highwaymen", you don't represent me (this is unequivocal as my life is mine and not state owned). You may have superior forces and may apply those betimes, but superior force does not a legal state make.
Legal does not equal most powerful. I'm sure you'll disagree with this, but it isn't much of a stretch.
Again, as I've said in the past, if "might makes right" then why not just dispense with the laws? Who are you trying to kid anyway? That's the entire sum total of your argument.
If the state only acts on behalf of those who voted for the last government, on what authority does it lock up the violently mentally ill? Does a fireman check if you voted correctly before attending to a fire in your area? What if you changed your mind and now want the fireman to save your family - can you announce you renounce your vote?