For years, political advertisers have benefitted from a loophole big enough to drive a $10 million-dollar political campaign through. "Issue ads" that don't explicitly ask for a vote for or against a candidate, and don't run immediately before the election, don't have to be disclosed to the Federal Election Commission.

But new rules requiring about 15 percent of the country's broadcast TV stations to disclose these ad buys online are beginning to pull the veil off this secret spending. And, the documents help make clear, the line between "issue ads" and the endless campaign is vanishingly ...