Of course his ego is hurt.  First he lost the popular vote but refuses to admit it - claims that he would have won the popular vote if not for millions of illegal voters.  Despite a shred of evidence Fox and the rest of his supporters seem to have swallowed that hook, line and sinker.

Then there was Comey of the FBI that released a memo re Hillary's emails immediately before the election.

And there was the Russian hacking.

And of course there were the efforts of GOP state legislatures to suppress minority voters.

Since he won 3 states by less than 1% and one other by less than 2% it's hard to argue that the election results are legitimate or that he has any sort of mandate.