Voting for mayor or for local elections is a completely different process as opposed to voting for president. If you're voting for a mayoral or local election, your vote is directly counted (allegedly). That isn't the case for presidential elections.
No, I have no idea why you're using Mamdani as an example. You clearly know less about how our government works than the average American. Please do some googling before returning to this conversation, I will not reply until you know what I'm talking about and can respond to what I'm actually saying to you.