The following is a script of “Obamacare” which aired on Jan. 11, 2015. Lesley Stahl is the correspondent. Rich Bonin, producer.

This month marks one year since health insurance coverage under the Affordable Care Act began, and from the president’s point of view: so far, so good. More than 10 million Americans who didn’t have health insurance before have signed up. But congressional Republicans are gunning for Obamacare. Even if they can’t outright repeal it, they want an overhaul.