Republican-aligned outside group Crossroads GPS has launched an ad in North Carolina attacking Democratic Sen. Kay Hagan on the president’s health care law.  

The group said it put $3,550,000 behind the ad, which will run on North Carolina TV for four weeks. It’s the latest evidence that the race between Hagan and Republican state Speaker Thom Tillis will likely be the most expensive of the cycle.  

The ad, which began running Tuesday, attacks Hagan for saying people would be able to keep their insurance and doctor once the Affordable Care Act took effect — which turned out to not always be true.  

www.youtube.com/watch?v=w9Mj_N7D7Y4  

American Crossroads, the Super PAC associated with the nonprofit Crossroads GPS, spent heavily in support of Tillis during the primary, pouring $1.6 million into ads backing him. The ad is part of the groups’ $10 million campaign across several states with competitive Senate races.  

Hagan is a top target of national Republicans seeking to take control of the Senate. The race is rated Tossup by the Rothenberg Political Report/Roll Call.