He can’t legally raise the debt ceiling by himself under section 4 of the 14th Amendment because of section 5 of the 14th Amendment. Case Closed.
And...? You’re obviously working under the assumption that the US government operates within the confines of the constitution. With the possible exception of the 3rd amendment, fedgov stopped following those rules a long, long time ago.
And who will stop him? Who will stop him for doing whatever he pleases as he has since he took office???
exactly