I believe this is all a fishing expedition and witch hunt, but frankly, I have not heard a single good thing about Manafort, and plenty of bad things.
Granted,those bad things were by people in the Trump campaign who had reason to hold a personal grudge against him...but still.
He is the dirty one in the campaign (there was a reason Trump fired him) and the other two (Page and Papadopoulos) just sound inexperienced and ambitious (a dangerous combination when people are looking to stick a knife in your back)
Manafort hasn’t done anything hundreds of others aren’t doing on a daily basis in the influence peddling, carnival of whores known as DC.
Even his old business partners have nothing good to say about him. The reason he didn’t work in the USA since 1998 was that he had managed to cheat everyone and no one wanted to have anything to do with him.