In addition to what others have said he's now been ousted from Hungary so he is probably looking for a new revenue stream. Trump is hoping that he can use him to further his interests in Europe.

It's really dumb though, it's not as if Hungry hasn't been a thorn in everyone's aside for the last 20 odd years, everyone knows who he is, and what he's like. He's not going to get anyone's backing, he has been 100% pro Russia from the start, which means he's been making zero allies back home.

This isn't really newsworthy in and of itself, it's just another demonstration of who Trump is. There's basically zero chance he is actually going to get elected, so it doesn't really matter.