Is that a comb-over or what? Why doesn't he spend some of those billions he is always bragging about on a hair transplant or a weave or something? He wouldn't have to worry about the wind mussing his 'do any more and he could shitcan that stupid fucking ballcap he has started wearing to prevent shit like this:
I think it has become his trademark for so long he would now refuse to ever change it.
It seems it has been that way for years. It gives yhe cartoonist something to hone in on. Through the years, it has been LBJ's ears, Nixon's nose, Carter's grin, Reagan's wrinkles, Obama's ears to name a few.
The hair could be another way of him saying, "fuck you, deal with it".