But, without four commissioners, the agency’s regulation and enforcement of campaign finance laws — already badly compromised — will largely grind to a halt. The board will no longer have the ability to open new investigations. It will not be able to rule on whether laws have been broken, much less what penalties to impose. It will not be able to adopt new safeguards, such as to improve the transparency of online political advertising. Somewhere in Russia, the trolls responsible for the social-media chicanery of 2016 are smiling.

The harsh truth is that the commission has been a model of dysfunction for over a decade. Among the problems: Squabbling between Republican and Democratic commissioners increasingly results in gridlock over enforcing laws ; funding has long been stagnant; and poor staff morale has created a critical “brain drain.” The Center for Public Integrity has described the agency as “rotting from the inside out.”

That is an argument for reforming this vital agency, not letting it die.

Even in its denuded state, the F.E.C. could occasionally get the job done. This spring, it levied fines totaling $940,000 in a case in which foreign nationals were illegally involved in a $1.3 million contribution by an American subsidiary of their Chinese corporation to a political action committee supporting Jeb Bush’s 2016 presidential candidacy. The action not only held the involved parties accountable, it also sent a message that “there are rules, and they will be enforced,” said Trevor Potter, a former commission chairman and the president of the Campaign Legal Center, the watchdog group that filed the complaint.

The president should never have let the situation reach this point. One Democratic seat has been vacant since April 2017, a Republican seat since February 2018. Mr. Trump has named only one nominee, Trey Trainor — a Republican whose nomination in September 2017 has been effectively ignored by the Senate majority leader, Mitch McConnell.

It’s unsurprising that keeping the election panel well staffed is not among Mr. McConnell’s priorities. His antipathy toward campaign-finance regulation is legendary. To kick-start this process, Mr. Trump will need to apply a bit of pressure — and he will need to work with Senate Democrats and submit more than one nomination.