The phrase "to drain the swamp" means to eliminate corrupt and unethical practices or behavior from a particular system or organization. Full definition
«To speak of draining the swamps of Islamo - fascism through democratization of the whole Muslim crescent,» he writes, «was mad.» (firstthings.com)
«President Trump himself vowed that he was going to drain the swamp in Washington, and ironically, his number one supporter — Chris Collins — is the epitome of an unethical self - promoter who has literally accomplished nothing for the people of the 27th District, the very people he's supposed to represent,» Cole said. (buffalonews.com)
, we need not drain the swamp — but I hope we can avoid the quagmires, and cut through some of the jargon. (slaw.ca)