In what tea party groups are calling a "battle to save America from the Obamacare 'train wreck,'" Republican lawmakers plan to appear at a Capitol Hill rally on Sept. 10 to promote a proposal to defund the Affordable Care Act.

Filibuster_Fight-0c916_image_982w Sen. Mike Lee (R-Utah) and Sen. Ted Cruz (R-Texas) (AP Photo/J. Scott Applewhite)

Republican senators Rand Paul (Ky.), Mike Lee (Utah) and Ted Cruz (Tex.) will headline the "Exempt America Tour" rally on the West Lawn as a culmination of a five-day tour of six states. The tour, which will kick off in Kentucky on Tuesday, is sponsored by seven tea party groups, including Tea Party Patriots and For America.