I 100% support anybody who says “Donald Trump is not my president”. That is a completely valid view. If other people select as president somebody who you find unacceptable, you are not obligated to accept them, and you don’t have to listen to anybody who tries to shame you for that.
But I also 100% despise anybody who thinks that because their preferred candidate lost an election, that they should stamp their wittle feets and demand that the election be overturned. That’s not dissent it’s just childish bullying.
Donald Trump isn’t your president? Good. I agree. He ain’t mine, either. And these people in blue states (or counties or precincts etc) that don’t want him absolutely should not accept him or give him any legitimacy or authority. They should secede and then they can vote for whoever they want to be their president, if indeed they are truly so desperate to have one.