So, I've never liked that phrase. What happens when you drain a swamp? You remove all the stagnant water and dead-zones. But what is left behind? He said he would drain the swamp, not remove the scum.

This is what I really don't get, what did he do while in power for 4 years? Surely if he was voted there to drain the swamp and then didn't, it makes him in ineffectual leader, so why vote for him again? Get someone else in to drain the swamp and this time do it right.

He drained it so he could fill it with his own swamp.