Congressional Budget Office expected to release costs, coverage estimates of GOP health care bill

— -- As President Trump and House Speaker Paul Ryan grapple to keep their own party on board with the Obamacare alternative they unveiled last week, Democratic lawmakers are decrying the proposed law as a blow to lower-income Americans.

In the end, the bill's success may hinge on the math.

The Congressional Budget Office is expected to release its assessment of the GOP's plan, the American Health Care Act, as early as today. The nonpartisan report will include an estimate of the law's cost and statistics on how many Americans will lose coverage under the new plan.

Of course, the CBO isn't the only organization crunching the numbers.

Ratings agency Standard & Poor's last week released a report predicting between 6 million and 10 million people would lose coverage under the GOP's plan. Some liberal think tanks, like the Brookings Institute, put that number even higher.

Democrats, confident that the CBO's forecast will paint a similar picture, have blasted Republicans for marking up the bill without a CBO score.

But the Trump administration has been preemptively undermining the CBO's credibility, pointing to flaws in the office's early assessments of the Affordable Care Act.

The CBO has been "woefully underperforming when it comes to evaluating health systems," Health and Human Services Sec. Tom Price said on Fox News Friday.

"I love the folks at the CBO. They work really hard, they do, but sometimes we ask them to do stuff they're not capable of doing," White House Office of Management and Budget Director Mick Mulvaney told ABC's George Stephanopoulos on Sunday.

"Look at how off they were last time," White House Press Secretary Sean Spicer said at Wednesday's press briefing. "If you're looking at the CBO for accuracy, you're looking in the wrong place."

While Spicer -- and the president, for that matter -- have cited CBO statistics to bolster their agenda in the past, their current skepticism is not without some basis: Some of the office's initial predictions about Obamacare were off the mark.

When the healthcare law passed in 2010, the CBO projected that about 21 million people would purchase coverage through the new exchanges by 2016, and after the Supreme Court ruled the Medicaid expansion optional for states, it increased its projection to 22 million. In actuality, just over 11.5 million people have purchased coverage that way, according to an HHS report.

In the same projection, the CBO put the number of uninsured at around 21 million by 2016. But according to preliminary data from the CDC, more than 28 million people remained uninsured in the first three quarters of 2016.

On Sunday, Ryan acknowledged that the CBO's analysis of the Republican healthcare bill would likely include the projection that many Americans would lose coverage.

"CBO will say, well, gosh, not as many people will get coverage," Ryan said on CBS's Face the Nation. "You know why? Because this isn't a government mandate. This is not, the government makes you buy what we say you should buy."

"There's no way you can compete with, on paper, a government mandate with coverage," the Speaker added. "What we are trying to achieve here is bringing down the cost of care, bringing down the cost of insurance, not through government mandates and monopolies, but by having more choice and competition."

So how many people will lose coverage?

"I can't answer that question," Ryan said. "It's up to people."