Nearly three years ago, during my tenure as vice chairwoman of the Federal Election Commission, I wrote in this newspaper that my own agency was failing to enforce campaign finance laws. My efforts to cooperate with the other commissioners to fulfill the agency’s mission had been thwarted, revealing an unfortunate truth: The F.E.C. was betraying the American public and jeopardizing our democracy.

It pains me to report that the agency remains dysfunctional, more so than ever, as I prepare to depart at the end of this month as my term nears its end. This is deeply worrisome, because the F.E.C.’s mission is to ensure fairness in elections. One of its core responsibilities is to make sure that all money in political campaigns is disclosed. As Justice Louis Brandeis said, sunlight is “the best of disinfectants.” This quotation graces the street-facing window of the F.E.C.

Unfortunately, a controlling bloc of three Republican commissioners who are ideologically opposed to the F.E.C.’s purpose regularly ignores violations or drastically reduces penalties. The resulting paralysis has allowed over $800 million in “dark money” to infect our elections since Citizens United, the 2010 Supreme Court decision that allowed corporations and unions to spend unlimited sums to elect or defeat candidates.

These commissioners have been enabled by the commission’s very structure. By law, no more than three of its six members can be from the same party. Four must agree to begin an investigation.