I think the problem is that being political correct is textbook bigotry and that the OP thinks of political incorrectness as bigotry shows how influential the dogma pushing it is. The problem that can arise from things deemed political incorrect is that people can be nasty about it.
Discussing certain matters of race, sex, religion, sexuality and politics are restricted by political correctness. You can't discuss many things, people will be intolerant of them, by definition this is bigotry.
Whether you hate or support Trump you need to admit that there is a lot of bigotry against those that supported him. It was not politically correct, your support would gather a great deal of hostility, the same cannot be said against those who did not support him.
You can study people who identify as transgender, you hold little bias and just report what you find. If you find that they are just as emotionally stable as the rest of us then your findings will be praised, if you found otherwise then your findings are politically incorrect and you will personally be attacked by the political correct, your career will probably be over. If you discuss matters of racism or discrimination against whites or men then you will gather little support or open hostility, it's not political correct.
At it's positive being politically correct means just not being a dick, you try not to use racial slurs or sexist remarks to attack. You don't preach about abortion to a woman who has just had one.
They are measuring sticks, you can be too much of one or the other