King was originally heavily favored to win the Maine Senate race, but the contest has looked more competitive recently as outside money (the U.S. Chamber of Commerce, the National Republican Senatorial Committee) has poured in money to target King. And more recently, the Democratic Senatorial Campaign Committee and Americans Elect have begun spending in the state as well, attacking Republican nominee Charlie Summers
and supporting King.
The Maine ad is part of a $5 million buy in seven Senate races. The other spots target Joe Donnelly
in Indiana, Jon Tester
in Montana, Shelley Berkley
in Nevada; Heidi Heitkamp
in North Dakota, Tim Kaine
in Virginia; and Tammy Baldwin
in Wisconsin (that ad will be released tomorrow).