This would be 24/7 on Fox and Republicans go crazy, if Obama still were president.
Pretty sure Hannity would be calling for Obama to be lynched over almost anything Trump has done.
As shameless as it is, people like Hannity are insulated by the goldfish-like attention spans of their audiences. They can bash Obama for taking vacations in 2016, then by 2017 be justifying Trump taking a vacation of the same length without batting an eye. Hannity knows his audience won't remember, if they ever knew what he said a year ago in the first place. It's even worse for comments/segments done several years ago.
Trump abuses this as much as anyone, as those tweets show. He says something dumb, moves on, and leaves everyone scrambling to point out his hypocrisy, at which time he's already said another dumb thing, and another, and another...