Because he can’t intimidate them.
People like trump get off on attention. They know everything about everything . They have all the answers. They’re so wise that they’re never wrong. Naive people gasp in awe at their seemingly sage words. The more the naïve gasp, the prouder these people become (inflating their egos). A person who actually IS smart or can see through their lies is a threat to them, as they may expose them for what they really are (twits), thus taking away their attention.
Trump is also a sexist. He thinks the only things women are good for is making babies and sandwiches, and praising men for how great they are. To him, women are to be seen, but not heard. That’s why he marries arm candy and then dumps them when they get “older” looking.
This is why strong women terrify him. To be shown up by an “inferior” female is the cruelest insult an egotistical sexist could get.