I've had this happen to me. They'll promote people, usually lazy young men, out of the department who have no business being promoted. They'll keep the people who actually know their job, do it really well consistently, and get stuff done.

Those guys will get promotions based on "personality" and "networking". You'll end up doing their job too because they're not competent. They'll make the pay that should have been yours.

There will be a lot of guilt and pressure if you let things tank as you should, and if you do that will preclude you from getting the promotion because now you're not a team player.

It sucks.