As Trump Press Secretary Sean Spicer put it in his opening salvo:

"If you're looking at the CBO for accuracy, you're looking at the wrong place.”

Spicer had plenty of company among Republicans now hurling invective at the CBO, an agency run by the GOP’s selected director, Keith Hall. Rep. Steve Scalise (R-LA), the House Majority Whip, said “we’re not going to wait” to vote because the CBO’s "unelected bureaucrats in Washington" will slow down the Republican promise to repeal and replace Obamacare. While Rep. Michael Burgess of Texas scoffed that the CBO “is hardly the final word on the issue,” South Carolina GOP Senator Tim Scott complained that Congress’s budgetary referee “is consistently inconsistent with the actual results of a 10-year window because life changes so quickly so I don't put that much weight on a CBO score.”

But as Sarah Kliff explained on Wednesday, “Republicans' problem isn't CBO. It's their bill.”

The coverage numbers aren't likely to be good — at least according to independent analyses from outside experts. And if the CBO analysis finds that the Republican plan will cover fewer people than Obamacare, Republicans are preparing to argue that the problem lies with CBO.

Of course, they’ve been doing that for years.

Consider, for example, the GOP reaction to Hall’s CBO assessment of the repeal of Obamacare in January 2017—that is, less than two months ago. Republicans were foaming at the mouth at the nonpartisan agency's conclusion that the repeal of Obamacare will be no replacement or placeholder for the Affordable Care Act and will lead to 32 million more uninsured Americans and a doubling of premiums. Speaker Ryan Paul Ryan (R-WI) called the analysis "meaningless," while Rep. Steve "David Duke Without the Baggage" Scalise (R-LA) fumed "The CBO report assumes no Obamacare replacement." That conservative apoplexy came less than a week after House Republicans instructed CBO Director Keith Hall—a man they themselves put in the job—not to "score" the budget-busting impact of their Obamacare repeal proposals. And within days, former House Speaker and current Trump bath-water drinker Newt Gingrich called for the dismantling of the nonpartisan scorekeeper, because "the Congressional Budget Office (CBO) is simply incompatible with the Trump era."

Of course, this right-wing vendetta against CBO is nothing new. From health care and taxes to the stimulus and immigration reform, Republicans have been waging a war against the CBO for years.

To be sure, Republicans have been raging against the CBO machine over Obamacare since its first assessments of the Patient Protection and Affordable Care Act beginning in 2009. It's no mystery why. From its earliest estimates in 2009, the CBO has always forecast that Obamacare would reduce the national debt. The math has always been straightforward. The 10-year cost of Obamacare (for Medicaid expansion, insurance subsidies, etc.) has always been less than revenue generated by new taxes imposed by the ACA and the significant savings extracted from Medicare insurers and providers. That's why CBO in June 2015 explained that repealing Obamacare would add "at least $137 billion or as much as $353 billion" in new deficits over the ensuing decade. As Sarah Kliff summed it up at the time:

"No matter how CBO scores it, Obamacare reduces the deficit."

So it comes as no surprise that Gingrich is now proclaiming "every reform will get a false score from CBO." After all, in November 2011 the short-lived GOP presidential frontrunner declared, "If you are serious about real health reform, you must abolish the Congressional Budget Office because it lies." The House Majority Leader Eric Cantor (R-VA) wasn't happy, either.

Charging that "most people understand that the CBO did the job it was asked to do by the then-Democrat majority," House Majority Leader Eric Cantor warned, "bill has the potential to bankrupt this federal government as well as the states." As CBS News reported in early 2011, Cantor quickly doubled down:

Cantor also disputed the claim, put forth by the nonpartisan Congressional Budget Office, that the health care reform bill passed by Congress last year will actually reduce the deficit by $143 billion, calling the figure "budget gimmickry." "I think what we do know is the health care bill costs over $1 trillion," Cantor told Hill. "And we know it was full of budget gimmickry. And it spends money we don't have in this country."

As Ezra Klein of the Washington Post explained at the time, "Republicans are aware that this looks, well, horrible. So they're trying to explain why their decision to lift the rule requiring fiscal responsibility is actually fiscally responsible."

What's important about Cantor's argument is not that he's wrong. It's why he's saying something he knows to be wrong. There are plenty of reasons to oppose the health-care reform bill. You might not want to spend that money insuring people, or you might not think the legislation goes far enough in reforming the system. But as a matter of arithmetic, using the math that Congress always uses, the bill saves money. It cuts enough spending and raises enough taxes to more than pay for itself, both in the first 10 years and in the second 10 years.

"Repealing health-care reform would cost hundreds of billions of dollars," Klein rightly concluded, "and Eric Cantor knows it."

If you have any doubt on that point, just look at the CBO's December 2015 assessment of Rep. Tom Price's H.R. 3762, the "Restoring Americans' Healthcare Freedom Reconciliation Act." When CBO scored H.R. 3762, it told Senate Budget Committee Chairman Mike Enzi that its Obamacare "repeal" provisions would reduce deficits by $474 billion between 2016 and 2025. Conservatives were overjoyed. But those giddy GOPers didn't acknowledge that their bill was only a partial repeal. They skipped over what Health Affairs rightly called "the $879 billion footnote." As that magic footnote in the legislation drafted by Rep. Fred Upton (R-MI) and Sens. Orrin Hatch (R-UT) and Richard Burr (R-NC) declares:

All provisions of PPACA and HCERA are repealed except for the changes to Medicare." (Emphasis added). [Note: PPACA and HCERA are the two statutory components of the law now known as the ACA -- or Obamacare.] [Emphasis mine.]

That difference, it turns out, makes all the difference. "Saving that single element," HA explained, "turns the CBO's current deficit raising cost projection for repeal from $137 to $353 billion negative to $449 to $665 billion positive." It's no wonder embarrassed Republicans don't want CBO scoring their new repeal legislation, or just don't want CBO at all.

That track record has left the GOP with only one sound bite left: the CBO overestimated the impact of the Affordable Care Act, a blown forecast which should be disqualifying. As Burgess put it, “The Congressional Budget Office in their own projections said 21 million people would be covered under the Affordable Care Act by the year 2016 [but] that number in fact was 10 million.” Energy and Commerce Chairman Greg Walden (R-OR) similarly protested to reporters that CBO said “21 million projected would be covered, but only 10 million people are covered.”

Many factors, GOP sabotage among them, explain the CBO’s overestimation of ACA sign-ups.

Sadly for Republicans, there are some major problems with their talking point. That CBO figure was for those purchasing private insurance through the Obamacare exchanges. Some 12 million Americans also obtained Medicaid coverage, a number which surpassed CBO estimates due to the “woodwork” effect whereby many actually eligible before the passage of the ACA ultimately signed up. Importantly, both CBO and the Obama administration overestimated the number of workers who would lose employer-provided coverage. And while Charles Gaba has explained that many wealthier subscribers purchased their unsubsidized policies from brokers and agents (that is, “off-exchange”), the ACA’s relatively low penalties for failure to obtain insurance doubtless were insufficient to drive sign-ups. And beyond the scope of any forecast was the impact of the GOP’s unprecedented obstructionism. Myths like “death panels” and a “government takeover of health,” negative ads targeting the “young invincibles,” multiple Supreme Court challenges that ultimately made Medicaid expansion optional, and sabotage of Obamacare “navigators” and “risk corridors” doubtless put a cloud over ACA enrollment.

Obamacare’s costs have consistently come in below forecast.

But there are two other inconvenient truths for Paul Ryan and his merry band of mythmakers. As the chart above shows, CBO consistently overestimated the costs of Obamacare. And as the Commonwealth Fund documented in 2015, the CBO’s projections weren’t just “reasonably accurate,” but were superior to those from other analysts:

The Congressional Budget Office (CBO), a nonpartisan agency of Congress, made official projections of the Affordable Care Act’s impact on insurance coverage rates and the costs of providing subsidies to consumers purchasing health plans in the insurance marketplaces. This analysis finds that the CBO overestimated marketplace enrollment by 30 percent and marketplace costs by 28 percent, while it underestimated Medicaid enrollment by about 14 percent. Nonetheless, the CBO’s projections were closer to realized experience than were those of many other prominent forecasters. Moreover, had the CBO correctly anticipated income levels and health care prices in 2014, its estimate of marketplace enrollment would have been within 18 percent of actual experience. Given the likelihood of additional reforms to national health policy in future years, it is reassuring that, despite the many unforeseen factors surrounding the law’s rollout and participation in its reforms, the CBO’s forecast was reasonably accurate.

This history has prompted Douglas Elmendorf, Keith Hall’s predecessor at CBO, to lament the current Republican smear campaign against the agency. As he cautioned US News & World Report:

"CBO's estimates of the ACA weren't completely accurate but they were more accurate than many people's random guesses. I see no reason why the Congress should rush to vote on important legislation without even looking at a CBO estimate. Estimates are intrinsically uncertain, especially for large policy changes. To take up a bill in committee of this importance without a CBO estimate is shocking to me."

Shocking to be sure, but all in a day’s work for the Trump administration and Capitol Hill Republicans. While Trumpcare is getting savaged from both right and left, Office of Management and Budget chief Mick Mulvaney for one is confident his former House colleagues will come around.

“The only question about the CBO: Is it going to be really good, or is it going to be great when that number finally comes out?”

We’ll see. But Mulvaney’s boss and congressional Republicans are clearly worried the answer from the CBO will be “neither.” As Spicer put it, “The idea that that's any kind of authority based on the track record of what happened last time is a little far fetched.” Which is why the GOP is already insisting any bad news forthcoming for the Congressional Budget Office can’t be trusted. After all, reality has a well-known liberal bias.