Bernie Sanders may never engage in the reformation of America’s health care system from a White House office. But his legacy may well include forcing Hillary Clinton to carry out some of his key health reform initiatives in order to keep Sanders from winning the Democrat’s presidential nomination.

Sanders has challenged Clinton to adopt several of his more progressive positions on health care reform, most notably the single-payer system for insurance. While Clinton hasn’t yet embraced single payer, this week she announced that she would support the Medicare buy-in concept that Sanders has also been pushing.

In Virginia, Clinton told an audience that she was in favor of the so-called “public option,” which would open up Medicare insurance coverage to people younger than 65. The option would permit younger people to pay part of the cost of Medicare coverage until they reach full coverage age, thus expanding less expensive insurance to more Americans.

The position clashes with Congressional conservatives’ efforts to raise Medicare enrollment standards and to include more cost-sharing for those insured, as a way to reduce overall government spending. However, studies have shown that such actions would like drive up the overall cost to the nation of medical services and health insurance.

Steve McMahon, a Democratic political consultant from Purple Strategies, told the New York Times that Sanders’ continued presence in the race is shaping what could be President Clinton’s policies, especially in the health care arena.

“Bernie Sanders’s campaign is having an effect on Hillary Clinton’s policies,” he says. “From a progressive point of view, that’s exactly what was hoped for and that is exactly what is happening.”