This is becoming a monthly event.

For the third time this year, the Federal Election Commission has served notice to the campaign of Sen. Sanders for making a mess of their [campaign] financial house. In the last two notices, the FEC noted over-limit and potentially illegal foreign contributions to the campaign, both with warnings of an audit.

But those egregious violation seem like typographical errors compared to the newest FEC notice to the Sanders campaign. The regulators have spotted more than $10 million that snuck into Sanders' campaign coffers from with no apparent accounting as to what it came from. Ten. Million. Dollars.

FEC's notice addresses Sanders' July 2015 campaign report, in which the campaign accounted for $3 million in individual, itemized contributions, but his full filing shows total itemized contributions of well over $13 million.