After Functioning for 28 Days, U.S. Election Regulator Will Be Powerless Again

With the swearing-in on June 5 of James E. Trainor III, a Republican lawyer from Texas, the agency was finally able to begin taking official actions, like addressing a backlog of potential violations relating to how campaigns raise and spend money.

When it was without a quorum, the agency continued to process robust financial disclosures detailing how much candidates had raised and spent this election cycle. With a quorum, the agency is additionally able to open and close investigations, impose penalties, defend itself against lawsuits and advise campaigns on how to comply with the law. Even when it has had enough members to function, however, it has frequently been criticized as toothless.

Ms. Hunter, whose resignation will take effect July 3, said that she planned to join Stand Together, a philanthropic organization founded by the billionaire Charles G. Koch. She has served on the commission since 2008, when President George W. Bush nominated her to the post. Her term technically expired in April 2013, and she and two fellow commissioners — one Democrat and one independent — have continued to serve beyond their respective terms while waiting for the president and the Senate to replace or renominate them.

In her letter to Mr. Trump, Ms. Hunter said that in her dozen years at the agency she had “fought to protect Americans’ First Amendment rights to free speech and association, and to administer the laws as written by Congress and interpreted by the courts, rather than as some wished them to be,” while also fighting “unnecessary government regulations and unfair enforcement actions.”

Some election lawyers and commissioners — including the agency’s only Democratic member, Ellen L. Weintraub — have described Republican commissioners as broadly uninterested in enforcing election law or conducting investigations, regardless of the political party of a candidate.