What the GOP is doing is nothing less than what they tried to do with Lincoln before the Civil War. To zero in on the most primal core of human fear, or that what is most different and unknown to the prevailing pale skin public.
The cartoons and fearmongering about lending equality to black skinned peoples from exotic lands far away was the only real weapon they had against a man who had bonded with so many. Even in the north, that was basically against slavery, racism of the kind lending to full equality was exploitable by southerners and their sympathizers before
Abe was finally elected and then re-elected, so it didn’t really work, but caused much more unnecessary divisiveness beyond Lincoln’s sole promise to end slavery by whatever means necessary.
Lincoln was never about granting full equality to blacks, just to end the practice of slavery. Notwithstanding efforts of his enemies to portray full equality as what he was secretly after. Sorta the same with Obama on about anything he’s for, it is warped into something false.
Now these same nativist whites who fear a loss of power are playing the same cards of rank skullduggery and loud and persistent fearmongering lies to reach that core of insecurity the majority white folks naturally have. Someone different that they, a person representing at once a chance for many to be free from overt bigotry that they have scratched and clawed out of not all that long ago, but also opening the possibility of sliding back into the paranoid grips of racial anxiety.
This second thing is what the wingnuts are banking on, though disguised with labels of commie, muslim, Nazi. or whatever. It is about race, added onto at least semi-legitimate political ideological disagreements. And what is surprising and what makes it so dangerous, is the Right Wing brain trust actively and passively promoting it, in some desperate hope it will win them back in favor and power from a country that has shown them the door without courtesy, for epic failures of governance.