Halloween's over. The FEC? Still a zombie.

These are dark times at the Federal Election Commission, which has now gone two months without enough commissioners to enforce federal campaign finance laws.

That’s because U.S. senators and President Donald Trump have failed to strike an agreement to fill any of three vacancies on the six-member commission that needs a quorum of at least four warm bodies to conduct most any high-level business.

The agency therefore can’t pass new rules, pursue investigations, issue fines, even hold formal public meetings.

What does this mean for political candidates, the...