Mad genius or sheer stupidity, I believe neither, for Trump all his life has believed that he and his family are invincible. Thinks appearing to be strong with am impressive Bank Balance, even though it may be only on paper or shear bluff will make him a winner every time.
He has used lying, strong arm tactics and disregard for Law and Order to get his way. He does not appear to fear bankruptcy for he has always used the US systems to come through. However, he can not comprehend that bringing the US down he will not be able to really on the systems for they may not be there.
Previously people would not cross Trump for if they did they would suffer, but in the heights of where he is now, there are many powerful people who will not succumb to his strong arm tactics and they will use the Law to counter Trump and they can not be bought.
Is Trump now close to meeting his match and if he is there will be no return, because his supposed powerful friends will not support a looser, for they then may loose themselves and this they will not wish to do.