Grievance group victim mentality: the act of putting yourself into as many categories of society that you possibly can, regardless of whether you actually belong there, that you can claim have been treated differently because of certain immutable traits, in order that you can be treated differently because of certain immutable traits. In other words, you claim it was wrong for others like you (or who you claim to be like) to be treated differently by the majority because of your race or gender or ethnicity or religion or favorite pizza topping or being fat or whatever, so therefore you (who in most cases did not get treated differently for any of these reasons) need to be treated differently by the majority because of this different treatment in the past. Which is how you fight racism. Or something.
And whoever checks off the most grievance group boxes wins.