In 2008, a veteran member of the Congressional Black Caucus, William Jefferson, ran for re-election with his trial on bribery charges mere months away. (The F.B.I. famously found $90,000 neatly hidden in his freezer.) Mr. Jefferson’s traditionally safe seat, anchored by the deep blue New Orleans metro area, was promptly ripped away by a moderate Republican.

And in 2006, the Republican George Allen, a former governor of Virginia and United States senator, lost his bid for re-election after he was caught calling an Indian-American who worked for his opponent’s campaign “macaca,” a dated but clearly derogatory term .

Considering how the current president launched his political career by questioning the citizenship of the first president of color — and has since called Mexicans crossing the border “rapists” who “infest our country,” African countries and Haiti “shitholes,” and protesting black athletes “sons of bitches ” — the end of Allen’s political career looks quaint.

The Keating Five scandal of the eighties, which ended the political careers of three senators with a combined 81 years of experience in Washington, is perhaps the most famous example of politicians losing their careers over their abuse of power. Senators John McCain and John Glenn alone survived it. But even that scandal — centering around loyalty pledges to a legally troubled donor — seems completely old-fashioned by today’s standards, in which donor influence is unfettered and lobbyists write bills themselves as President Trump stuffs his cabinet with plutocrats overseeing their own industries.

Mr. Collins’s war chest was filled with donations from the pharmaceutical industry as he crafted and sponsored bills to benefit his own pharma company. In five years, Mr. Collins introduced or sponsored at least five bills to directly buttress the company’s bottom line, and thus his pockets.

Yet none of this is mentioned in Mr. Collins’s indictment because none of it, shockingly, is illegal. And the “R” next to his name combined with his support for Trump was just enough to give him a win by two thousand or so votes in a decently red district.

Anticorruption legislation of the kind that would punish lawmakers trying to enrich themselves stands no chance with the Republican captain, Donald Trump, in the Oval Office. That leaves the 2020 elections as the next best shot. But the 2016 cycle — a period when the GOP surrendered its family and fiscal values for a philandering celebrity swindler and Democrats suddenly defended the state of money in politics when Hillary Clinton’s role in it was at hand — is a grim harbinger.