Groups opposing the GOP health care legislation have spent nearly $15 million on advertising since May in an effort to convince Republican senators to vote against the bill.
Advertising Analytics, an ad-buying tracker, said that groups opposing the Republican health care bill have spent $14.8 million on ads airing in the states of 13 key senators, NBC News reports.
No outside groups have spent money lobbying senators to support the bill in those states.
The lawmakers targeted the most are Republican Sens. Dean Heller (Nev.), Jeff Flake (Ariz.), and Shelley Moore Capito (W.Va.). More than a third of the spending has been aimed at Heller.
AARP, a retirees advocacy group, is the source of half of the funding against the bill so far. AARP has also promised to print every senator's vote in its bulletin, which the group claims is read by over 30 million people.
Save My Care, another group supporting the Affordable Care Act, has spent $2.9 million on ads.
Planned Parenthood has spent about $1.7 million.
