'Dark money' helps fuel litany of campaign ads in ... Maine?

PORTLAND, Maine (AP) — Millions of dollars in so-called "dark money" have propelled the race in the largest congressional district east of the Mississippi River to become the most expensive political contest in Maine history.

The race in Maine's 2nd Congressional District has attracted more than $12 million in spending by outside groups. That includes $2.3 million spent by liberal Patriot Majority USA, a group that doesn't have to disclose who funded its ads against Republican U.S. Rep. Bruce Poliquin.

Maine is also seeing more television ads than any other state. The Wesleyan Media Project says it boils down to 26 commercials per hour, or about one every two minutes.

Meanwhile, groups like the League of Conservation Voters that don't have to disclose their donors have donated at least $1.6 million for state-level races.