It's not a question of whether or not they notice, it's a question of whether or not they care. They don't vote for him because of his policies, they vote for him because he wants to hurt the people they don't like. They vote for him because "The Left" doesn't want him. He literally says his first day in office would be his Dictator Day and they ate it up.
I think they care, just not in a way normal people would - for Trump voters, it's 100% about trolling, annoying, hating, and secretly wishing dead anyone they deem to be the "outside group". And the worse Trump gets, the louder will that outside group's opposition to him be. Which in turn gives his followers great satisfaction.
So they care in a negative way, along the lines of "the people we hate and want dead will be so outraged by his gaffes, the news will be soo delectable to watch tomorrow! I'll come so hard watching them rage!!"