It is irrelevant as the number of bets placed on political events is usually much lower than the mainstream sports betting. Therefore most of the casinos offer such events just to show that they do care and listen to people, although these people are very few compare to what most people want. So for most people this thing if a casino keeps or not keeps the political events is not something that will make them go away to some other casino, only few individuals compared to the masses will be impacted by such choice.