Sometimes the best RPers don't make the best leaders. I don't think someone should stop RPing a particular trait/hatred/etc. just because that person is made a leader. If that trait gets in the way of leadership, then it's up to the Imm to recognize it and remove that character from a leadership role.

There are great examples of leadership killing characters because they couldn't roleplay the same way (e.g., Thresinok).

There are also great examples of leaders continuing their discriminatory practices after getting leadership, increasing RP as a whole (e.g., Taceolus, Niheriva). As long as players are willing to accept consequences (for Niheriva, losing leadership (not really a bad thing for Maran anyway since there's no real powerups) and for Taceolus, anathema) I seriously think that's a good thing.

Why don't you?