The end of 2017 has seen a spate of resignations from Congress, as Reps. Trent Franks (R-Ariz.) and John Conyers Jr. (D-Mich.) and Sen. Al Franken (D-Minn.) all stepped down or promised to step down due to sexual harassment allegations. All three did so under pressure from their own party. It shows that in between elections, the parties can indeed police themselves and don’t need to hide behind excuses of “letting the voters decide.”

Which brings me to Sen. Robert Menendez (D-N.J.), whose recent prosecution on corruption charges ended in a mistrial. Democrats should not wait for a new jury or Ethics Committee investigation: The known facts are damning enough for them to demand Menendez’s resignation.

In 2015, federal prosecutors indicted Menendez and his longtime friend and donor Salomon Melgen on corruption charges. According to the indictment, Menendez pressured executive branch officials to resolve disputes in Melgen’s favor. At the same time, Melgen and his family donated hundreds of thousands of dollars in campaign donations, and Melgen supplied all-expenses-paid vacations for Menendez to Melgen’s vacation home in the Dominican Republic. (In 2013, Menendez paid Melgen $58,000 to cover flight costs after media reports revealed some of the flights.)

Some of the alleged favors for Melgen were relatively small potatoes, such as securing visas for Melgen’s girlfriends. In one case, Menendez’s then-chief of staff wrote that the visas were approved “only due to the fact that R.M. intervened.” Other favors were far bigger. He asked the State Department to assist Melgen in a dispute over a $500 million contact with the Dominican government. The New Jersey senator also allegedly pressured the Department of Health and Human Services to resolve a $9 million billing dispute in Melgen’s favor. In testimony, then-HHS Secretary Kathleen Sebelius described an “unusual” meeting with Menendez and Sen. Harry M. Reid (D-Nev.). “I understood he wanted me to do something,” she said. (It should be noted that Melgen has been convicted of 67 charges of Medicare fraud. Prosecutors estimate that the doctor’s scheme swindled the government out of as much as $105 million.) In no way is this conduct becoming of a senator.

Given this damning evidence, why did the prosecution of Menendez result in a deadlocked jury? It helped that he had a high-powered defense team and bipartisan character witnesses such as Sens. Lindsey Graham (R-S.C.) and Cory Booker (D-N.J.). But Menendez should really be thanking the Supreme Court, which for years has steadily limited corruption prosecutions on First Amendment grounds. Where trading money for access was once considered sufficient for corruption charges, now the justices have narrowed it to specific cases of quid pro quo.

But the political sphere is not the legal sphere, and no party should be content with a standard of “not illegal.” Since the trial, the Senate Ethics Committee has resumed its enquiry into Menendez; many Democrats likely would prefer for that to run its course. But it is highly unlikely that new information for or against the senator will come out. With Capitol Hill Democrats rightly criticizing numerous instances of corruption in the Trump administration, it’s not much to ask that they stand up against similar cases in their own caucus. And it would show voters that Democrats aren’t satisfied with the Supreme Court’s narrow version of corruption. In a political climate in which voters on both sides are convinced that Washington is corrupt, this is a chance for Democrats to distinguish themselves as a party with standards.