Supreme Court Chief Justice John Roberts has again voted with his liberal colleagues to uphold a key portion of President Barack Obama's health care overhaul. Roberts also was the key vote to uphold the law in 2012. Justice Anthony Kennedy was a dissenter in 2012, but was part of the majority on Thursday. Roberts says in the majority opinion, quote, "Congress passed the Affordable Care Act to improve health insurance markets, not to destroy them." Nationally, 10.2 million people have signed up for health insurance under the Obama health overhaul. That includes the 8.7 million people who are receiving an average subsidy of $272 a month to help pay their insurance premiums. Of those receiving subsidies, 6.4 million people were at risk of losing that aid because they live in states that did not set up their own health insurance exchanges.