He has VERY thick skin. Many people would have crumbled under the withering attack he has not only survived but overcome.
One trait that supports this is his willingness to look ignorant or inconsistent. He simply doesn't care. He is sufficiently confident in his own abilities and dares to use his authority to get things done.
Later, after the battle has been fought, we may find Trump suggesting that violating due process is a bad idea and that he appreciates his advisers setting him straight. He can further point out that further investigation shows that such violations wouldn't even have been necessary in the Parkland incident; there are already laws against making terrorist threats or assaulting someone with a gun.
Getting his opposition to overstep their own best interests is part of Trump's art. We'll see.
I think you’re right.
People should not underestimate Trump.