Heritage Action officially backs House shutdown threat over ObamaCare

Republicans increasingly see the looming fight over a continuing resolution as the last opportunity to kill ObamaCare before its major provisions take effect.

Partisan brinkmanship could mean down-to-the-wire negotiations over how to keep the government running after Sept. 30. 

The conservative Club for Growth joined Heritage Action in supporting the GOP strategy on Wednesday.

Both groups are influential in Republican primaries and appear likely to oppose members who do not take dramatic steps to thwart the healthcare law.