But Tea Party Patriots said it will not support any GOP senator who agrees to fund the federal government if ObamaCare is included.
"For any Republican Senator to not join Sen. Lee by pledging to oppose continued funding for ObamaCare, it would be like saying, 'I was against the bill before I was for it,' " Martin wrote.
For America, led by Brent Bozell, also signed the letter.
— This post has been updated. A previous version misidentified Tea Party Patriots National Coordinator Jenny Beth Martin.