Obama warns GOP on healthcare: 'Now comes the hard part'

President Obama said he thinks Republicans' efforts to repeal and replace ObamaCare will get harder now that they have the responsibility of governing.

At a press conference Monday, Obama noted that while repealing his signature law has long been a “holy grail” for Republicans, the GOP will have to contend with the real-world consequences such action would have for the 20 million people who gained health coverage under the law.

In addition to winning the White House, the GOP also maintained its House and Senate majorities.

“It’s one thing to characterize this thing as not working when it’s just an abstraction, now suddenly you’re in charge and you’re gonna repeal it,” Obama said. “OK, well what happens to those 20 million people who have health insurance? Are you going to just kick them off and suddenly they don’t have health insurance?”

He pointed to other benefits of the law, such as slowing the growth of healthcare costs.

Obama acknowledged that the law could be repealed and replaced with something else. But what that replacement would be, he said, is key.

“My view is that if they can come up with something better, that actually works and a year or two after they’ve replaced the Affordable Care Act with their own plan, that 25 million people have health insurance and it’s cheaper and better and running smoothly, I’ll be the first one to say that’s great, congratulations,” Obama said.

“If, on the other hand, whatever they’re proposing results in millions of people losing coverage and results in people who already have health insurance losing protections that were contained in the legislation, then we’re gonna have a problem,” he added.

Republicans have not yet specified the details of their replacement plan.

President-elect Donald TrumpDonald John TrumpGOP-Trump trade fight boils over with threat to cars Trump: Meetings on potential North Korea summit going 'very well' Freed American 'overwhelmed with gratitude' after being released from Venezuela MORE told The Wall Street Journal last week that he wanted to keep the law’s protections for people with pre-existing conditions, a decision he said came after discussing the matter with Obama at their post-election White House meeting.

But it is unclear how Republicans would make that work if they repealed other parts of the law that interlock with that provision.

Speaker Paul RyanPaul Davis RyanRepublicans are strongly positioned to win Congress in November Don't let them fool you — Republicans love regulation, too Senate harassment bill runs into opposition from House MORE (R-Wis.) told CNN on Sunday that the specifics of a replacement are still being worked out.

“You're asking me details about legislation that hasn't been written yet,” Ryan said when asked if ObamaCare’s requirement that birth control be available to women at no cost would remain.

In a sign of how difficult coming up with a specific replacement is, Republicans could repeal ObamaCare with a delay -- giving them two years, or some other period of time, to try to come up with an alternative.

But Obama warned that Republicans will pay a political price if they take coverage away from people, saying “the American people will respond.”

“So I think on a lot of issues, what you’re gonna see is: Now comes the hard part,” Obama said. “Now is governance.”