A coalition of environmental groups is launching a $5 million push to help their Senate allies and to fight back against attacks from Americans for Prosperity, the conservative group backed by the billionaire energy moguls Charles and David Koch.
All three are in tight Senate battles and have been the targets of millions of dollars in negative ads from Americans for Prosperity.
The ad for Hagan attacks "oil industry billionaires" who "want to undermine the air safety standards that protect us," while the Michigan ad touts Peters's support for the Detroit auto bailout and for backing investments in renewable energy fuel.
The group is also airing ads supporting Sen. Susan Collins (R-Maine), who is favored to win her race this fall.
"We want to thank these lawmakers for providing strong leadership that promotes clean energy and protects clean air," said Environmental Defense Fund Vice President Elizabeth Thompson in a statement.
The groups will also coordinate an 11-state field program to help turn out the vote for their candidates this fall.