The biggest corruption-related political news in the United States over the past couple of weeks is the decision by the Department of Justice (DOJ) to indict Senator Bob Menendez (Democrat of New Jersey) for allegedly taking bribes (including cash, gold bars, and a luxury car) from several businessmen, in exchange for using his influence to help these businessmen in various ways. If you’re having a sense of déjà vu, it’s because we’ve seen this movie (at least the beginning) before: Back in 2015, the DOJ indicted Senator Menendez for accepting lavish gifts from a wealthy friend and campaign donor, allegedly in exchange for using his influence to help advance that donor’s personal and business interests. That prosecution was unsuccessful: The DOJ pursued the case, but although the prosecutors prevailed on some important issues of law, the trial, which took place in 2017, ended in a hung jury—presumably because some of the jurors did not think that prosecutors had proved, beyond a reasonable doubt, that the luxury trips and gifts bestowed on Senator Menendez were bribes, rather than personal hospitality offered by a close friend.

It remains to be seen whether the legal outcome will be different in this case (and of course, it should go without saying, Senator Menendez is entitled to the presumption of innocence in a court of law, though he is entitled to no such presumption in the court of public opinion). But there is already one notable difference between the current case and the 2015 case: the reaction of Senator Menendez’s colleagues in the Democratic party. As I write this (several days before the post will likely be published, so forgive me if this is a bit out of date), a number of prominent Democrats, including New Jersey Governor Phil Murphy, several Democratic Senators, and numerous Democratic House Members, including former Speaker Nancy Pelosi, have called on Menendez to resign. To be sure, as a critics have noted, several leading Democrats—including President Joe Biden and Senate Majority Leader Chuck Schumer—have not called on Senator Menendez to resign. But this is still a marked contrast from 2015, when to the best of my recollection (and readers should feel free to correct me if I’m wrong) no prominent Democrats called on Senator Menendez to resign. Why the difference?

There are several possibilities: The recent allegations are more salacious and more troubling (especially because they suggest that Senator Menendez improperly influenced arms sales decisions and passed sensitive information to foreign nationals), and the evidence of wrongdoing appears to be much stronger. But it seems to me that there’s another fairly obvious reason why prominent Democrats, especially in Menendez’s home state of New Jersey, have been much more willing to call for his resignation this time around than they were last time: the impact that a resignation would have on the balance of (partisan) power in the Senate.

In New Jersey, as in most states, the Governor has the power to fill a vacant Senate seat. Back in 2015-2017, the Governor of New Jersey was Republican Chris Christie, so Menendez’s resignation would likely have increased the Republican edge in the Senate from 54 to 55 Senators. (Additionally, the replacement would have had the advantages of incumbency at the next election.) Today, New Jersey’s Governor is Democrat Phil Murphy, so if Menendez were to resign, it would have not cost the Democrats their Senate majority. It is of course impossible to know for sure how much this factor explains the difference in the reaction of Menendez’s fellow Democrats this time around. But given that the Senate is divided 50-50, with Democrats controlling the chamber only by virtue of Vice President Harris’s tiebreaking vote, I seriously doubt that many (any?) Democrats would be calling on Senator Menendez to resign if a Republican governor had the power to choose his replacement.

And you know what? I don’t have a problem with that. As I’ve argued before (in a rather different context), some things are more important than corruption. This may be a controversial thing to say to an audience of (mainly) anticorruption experts and activists, but it is entirely rational, not only for politicians but also for citizens, to care more about how a given elected official will affect public policy outcomes—which could have profound effects on huge numbers of people—than about the personal integrity of that official. And this is true even if the alleged corruption at issue is not merely personal, venal misbehavior or immorality (comparable to, say, a sex scandal), but also has adverse impacts on the public welfare. Even if those adverse effects are real and important, they may be outweighed (in the eyes of many) by the adverse effects of shifting political power to other politicians.

This observation is hardly new. Although voters repeatedly claim that they dislike corruption and would vote against corrupt politicians—when the question is asked in the abstract—in real elections, voters in many countries regularly elect and re-elect candidates of questionable integrity (to put it mildly). Democracy is always not the anticorruption cleansing force that people sometimes imagine it would be. And that leads to another observation—again, not exactly new, but perhaps underappreciated: In the presence of intense political polarization (whether along ideological, ethnic, or other lines), it is unlikely that political elites or ordinary voters will be willing to discipline a corrupt politician on their side, unless it is possible to select a replacement who is similar on other important dimensions (such as partisan affiliation, political ideology, or perhaps salient demographic characteristics).

Returning to the specific context of the resignation and replacement of U.S. Senators for one application of this general idea: The 17^th Amendment of the U.S. Constitution allows the legislature in each of the fifty states to choose the means for filling vacant Senate seats, and most states, including New Jersey, allow the governor to fill a vacant seat through direct appointment. But some states use a different approach. Four states (North Dakota, Oregon, Rhode Island, and Wisconsin) require vacancies to be filled only by a special election, with the seat remaining vacant until the election is held. And in 11 states, the governor is required to choose a replacement of the same Senator who previously held the seat. That latter rule strikes me as a very good idea, at least from an anticorruption perspective. It makes it far easier for party leaders to withdraw their support for a Senator who is implicated in significant wrongdoing, but whose home state governor is, at that moment, a member of the other political party. I have no idea whether Democratic lawmakers will end up putting enough pressure on Menendez that he is forced to resign—he has declared that he won’t—but as I noted above, I feel very sure that there would be an approximately 0% chance that Democrats would seriously pressure Menendez to resign if his replacement would be a Republican. That something so consequential should turn on which party happens to control the state governorship at any given time seems like bad institutional design.

The point is broader, though. When thinking about the design of electoral systems, from an anticorruption perspective, it may be important to look past general elections between individual candidates, where partisan or other factors may (rightly!) swamp considerations related to corruption. Ideally, one would want a system where political elites and voters have more opportunities to replace corrupt politicians with alternatives who have similar ideological and/or demographic profiles.