The irony here is that all of the surveillance apparently related to his work with foreign governments ... which means he wasn't just a denizen of OUR swamp, either.
One interesting aspect of all this was that the warrant to conduct surveillance against Manafort apparently came through a secret FISA proceeding. This gives President Trump a perfectly reasonable response to any political criticism he gets over this whole thing: "I never would have hired him if I knew he was the subject of an FBI investigation, but since that whole process was a secret one I had know way of knowing anything about it."
The interesting thing is, they were surveilling him since 2014 and nothing until now. Funny how that works.
Manafort was an insider, as you say, and as such, would actually never have been subject to any investigation - except that his association with Trump led them to hope they could get at Trump through him.
Your point is a good one about giving Trump a good response regarding his hiring, though. Maybe their secrecy and general all-over sneakiness will backfire on them. One can only hope...
That and Trump fired the guy...
Long before the Russian narrative heated up, too.
Pretty easy to say the dude was crooked and when I found that out, I booted him.