He says there's no check on how the House conducts impeachment. It has absolutely authority and it doesn't matter how it reaches a decision to impeach. Then they call Trump a King because he wants adjudication in an article 3 court.
The irony could squash him like a bug if dropped on his head.
Schiff might think that's a clever answer, but what he essentially saying is that the House can bring a big bag of dog poop and drop it on the Senate floor, and they have to dig through it to find out whether or not the dog ate their homework.
I really don't think the Senate wants to do the House's dirty work.