The 113th Congress will be the first one in 40 years to convene without California Congressman Pete Stark as a member. Stark was defeated in November by a fellow Democrat under new California voting rules. Stark may not be a household name. But he leaves a long-lasting mark on the nation's health care system. So just how influential has Pete Stark been on health policy in his four decades on Capitol Hill? Very, says John Rother, head of the National Coalition on Health Care. Stark has "been part of almost every piece of health legislation that's been enacted, including the Affordable Care Act," Rother says. "And many of the changes and improvements in Medicare trace to him as well."