Hmmm.... it didn't mention that Obama and Cli..

4 yrs

Hmmm.... it didn't mention that Obama and Clinton certainly talked smack about Trump.
https://definition.org/former-presidents/

Former Presidents Must Follow These Rules After Leaving Office

Former Presidents Must Follow These Rules After Leaving Office

Being the president of the United States of America has got to be one of the hardest jobs on earth, and even former presidents have some pretty strict rules they have to abide by after departing the White House!