In the minds of many, politicians are supposed to cater to every one of the voters in their district, even the ones that didn’t vote for them. And by “cater to”, I don’t mean to wait on them hand and foot, but merely to treat with respect.
More to the point, we expect our politicians to be professional enough to set aside their personal feelings and act for the greater good of society as a whole and to minimize the harm when the benefits of the many must come at the expense of a few.
When a politician speaks as Trump does, that may earn you points for honesty, but it also comes across as unprofessional. And amongst non-politicians, “political incorrectness” marks one as ignorant of the whole concept of how societies work. At best, it leads to serious questions on whether one is informed enough to deserve the power to vote. Ideally, votes are cast by informed voters who understand the issues well enough to determine which candidate would best serve them. In reality, we have a depressing number of uninformed voters who vote based on the same sort of sound bites that you get in advertising without ever doing any sort of critical thinking before casting their ballot.
While one can overlook a certain amount of “political incorrectness” amongst average people, it’s harder to overlook that flaw if you intend to be put in a position of power. While those tactics will solidify support amongst those who strongly agree with you, it will alienate just about everyone else, even those who do agree with you but think you’re just not fit to be in office due to your lack of professionalism.
In Trump’s case, it’s made a bit more egregious given the sheer size of the demographic he is offending. It’s not like he’s discriminating against left-handed lesbian eskimos, of which there are few enough to be ignored at the polls. No, he’s going after about one-sixth of the US population; a large enough voting bloc that no intelligent politician would risk offending unless they had strong support among the other 83%. Trump’s support is pretty weak outside of those who vote straight-ticket Republican on everything, so it’s basically political suicide. Yet the fact that he is the frontrunner tells you quite a bit about the base; the sort of things that will make swing-voters vote for his opponent right now without even knowing who the Democratic nominee will be. While one may debate the exact mix of stupidity and insanity involved in that political strategy, the simple truth is that the majority of people would rather have a more professional politician in office.
I guess it all boils down to whether you prefer your politicians to give you the finger outright and screw you blatantly or to at least respect your intelligence enough to try and be sneaky. Ideally, politicians wouldn’t screw us at all, but this isn’t an ideal world.