CPI:

On Tuesday, a pro-Hillary Clintonsuper PAC sent campaign regulators a seemingly perfunctory letter, all of 30 words long.

“This letter serves to officially notify the Federal Election Commission that Priorities USA Action will file its reports on a monthly basis to the Commission as of January 1, 2016,” it read.

Sounds harmless enough. But that little note — and more just like it from other super PACs — allows top presidential bankrollers to remain hidden as the campaign grows white hot.

That’s because, thanks to a quirk in federal law, such letters give those super PACs the power to withhold their January donors’ names until well after the first-in-the-nation Iowa caucuses and New Hampshire primaries are conducted next month.