Rep. Tom Price (R-Ga.) has no shortage of charts, bullet points and studies to back up the GOP’s tax strategy, all of which he laid out Tuesday afternoon before a room of reporters. But, perhaps most prominently, Price wielded numbers from the Congressional Budget Office to make the case for extending all the Bush tax cuts permanently, as the House is poised to vote on this week.

Rep. Tom Price (R-Ga.) (T.J. Kirkpatrick / Getty Images)

"As the Congressional Budget Office has said, the growth rate if these [tax hikes] go into effect is 0.5 percent," Price told reporters. "If we're able to keep the rates the same, the growth rate is 4.4 percent."

It's not surprising that a legislator would rely on numbers from the CBO, given the office's long-standing reputation as a non-partisan, independent scorekeeper. But in the next breath, Price dismissed another major finding from the very same number crunchers.

When asked how the GOP would make up for the huge increase in the deficit that would result from making the Bush tax cuts permanent—which the CBO estimates will reduce revenues by $4.6 trillion—Price flatly denied that the numbers were valid. "We don't believe that keeping tax rates as they are right now costs money,” he said. Instead, he explained, preserving all of the Bush tax cuts would spur tremendous economic growth that would quickly fill the deficit gap. “What happens when the economy grows, is the federal government actually gets more tax revenue.”

So how is it possible to tell which CBO numbers to trust? I asked Price, pointing out the discrepancy. “The CBO is constrained by rules, in some instances,” he explained. “Sometimes the rules allow them to have more accurate information, in others they don’t.” When it comes to analyzing tax revenue, the CBO must follow the guidance of the 1974 Budget Act, which Republicans like Price believe is flawed.  Instead, they’ve long advocated for what’s known as “dynamic scoring” to account for the revenue impact of the economic growth they believe that tax cuts will accelerate.

Why, then, were the 1974 rules for scoring taxes imposed in the first place? Were people just misinformed? Price shrugged, pointing out that Republicans on the Budget committee have tried to change the rules 10 separate times.

In fact, the Bush administration tried using the GOP’s preferred dynamic scoring method to look at the very same Bush tax cuts in 2006. But the results disappointed conservatives: There wasn’t the strong correlation between growth and tax cuts they had expected, and there were far lower levels of growth attributed to the tax cuts than Republicans had claimed, particularly when they weren’t offset by other budget cuts. Even Doug Holtz-Eakin, then a GOP-appointed CBO director, didn’t clamor for more dynamic scoring thereafter.

But that hasn’t stopped Republicans from using the logic of dynamic scoring to make the case for tax cuts that aren’t offset by anything else, as they’re proposing once more. It’s a position that everyone from Tom Price to Mitt Romney has embraced, whatever CBO says to the contrary.