That is a lie straight from the lips of hell. You DO NOT have to vote for one or the other.
A heresy is a school of thought, among Christians there are many schools of thought however we should all have the same items of the faith.
For example, Pau taught that women should wear a head covering while in the meeting of the church, but also said if anyone is argumentative over this then we have no such custom. He was saying this is not an item of the faith, therefore don't make this an issue to fight over. On the other hand Jesus is Lord is an item of the faith and that is where we draw the line, it is an item of the faith that we should fight for.
Your teaching that Christians should not vote for the lesser of two evils is a school of thought. Very few subscribe to this, but certainly not something I would fight over. Because it is not an item of the faith.
But once you indicate that voting for one or the other leading candidate in an election is a lie from the pit of hell that is dfferent. You are now elevating this to being a work of the flesh and just as those who make lies and love lies are excluded from the kingdom of the heavens the implication is that voting for one or the other will impact a persons salvation and standing before the Lord. You are now judging the Lord's servants. If the Lord spoke to you to not vote, that is fine, but you don't have the standing to tell other servants of the Lord what they can and cannot do, that usurps the Lord's position in their life and it is rebellion against Jesus who is Lord.
Everyone knows your stance on this, you have told us a hundred times. But you are not the Lord, you do not have the right to speak on behalf of the Lord, and this post of yours offended me. I consider it offensive, and not just a heresy, but a damnable heresy.