Donald Trump has said many times he wants to “drain the swamp.”

Drain: cause the water or other liquid in (something) to run out, leaving it empty, dry, or drier.

Dredge: clean out the bed of (a harbor, river, or other area of water) by scooping out mud, weeds, and rubbish.

Given the folks he’s put in his cabinet, maybe he does mean drain – he’s draining the water which might otherwise clean the swap, leaving only the mud, weeds, and rubbish.