Democrats on Capitol Hill budget panels are loudly praising the Congressional Budget Office’s (CBO) new “dynamic” scoring of President Donald Trump’s Big Beautiful Bill Act of 2025 (BBB) for confirming their talking points that the proposal disproportionately benefits the wealthy, while ballooning the national debt.

“Today’s CBO score will disappoint every Republican who hoped tax breaks for billionaires would magically pay for themselves,” said House Budget Committee Ranking Member Brendan Boyle (D-Pa). “Their handouts to the mega-rich will add trillions to the national debt. As if kicking 16 million people off their health care wasn’t bad enough, now every American will pay the price for the Republican debt crisis, with higher interest rates, bigger credit card bills, and more expensive mortgages.”

Senator Jeff Merkley (D-Ore.), the top Democrat on the Senate Budget Committee, could not be reached for comment, but in a June 12 statement on a related CBO analysis done at his request, the Oregon lawmaker condemned the BBB, saying, “Every day, we see more and more evidence that this bill is all part of the Republicans’ Great Betrayal of American families. CBO’s independent and nonpartisan analysis shows that this bill will overwhelmingly benefit millionaires and billionaires while hardworking middle-class families get cut off from health care and food assistance.”

The June 17 analysis, which CBO described as a “dynamic estimate” of the economic and budgetary effects of BBB if it becomes law, projects that the national debt would be increased by $3.3 trillion, thus reaching 124% of the nation’s Gross Domestic Product (GDP). Earlier this year, using what economists refer to as a “static” analysis model, the CBO projected the BBB’s enactment would drive up the national debt to 117% of GDP.

Either way, the national debt would reach its highest level since World War II under the BBB, according to CBO. The agency also projected that annual GDP growth would only average 0.5%, while interest rates on 10-year Treasury bonds would be 14 basis points more expensive and inflation “would increase by a small amount through 2030.”

Essentially, the key issue in the scoring debate is the issue of relying on “static” versus “dynamic” economic models in CBO’s scoring of legislation. The former approach — considered to be the “conventional wisdom” among traditionalist Keynesian economists — assumes basic factors in the economy essentially will remain constant regardless of changes on the policy side, such as tax cuts and hikes.

The dynamic approach — which is associated with Supply Side economic theory — seeks to factor into projections, for example, the revenue effects of a changed tax rate, the costs of regulatory compliance, investment patterns, and a host of other often highly variable factors.

The issue came to the fore in 1981 when then-President Ronald Reagan — an enthusiastic Supply Side advocate — proposed what was then the biggest across-the-board tax cut in American history. Relying solely on static analyses, CBO projected the tax cuts would reduce government revenues and increase the national debt.

Democrats in Congress and the mainstream media blasted Reagan’s proposal, citing the CBO scoring and predicting dire consequences, while Republicans claimed lowering taxes would give people more money to spend, which would in turn grow the economy and produce higher tax revenues. In fact, revenues were increased substantially due to the rapidly expanding economy of the Reagan era.

The pattern has been repeated regularly in the decades since, as Republicans during the second Bush administration and in Trump’s first term lowered taxes amid CBO projections and Democratic predictions that the government would “lose” revenue, causing deficits to grow and slowing job growth.

As happened with the Reagan cuts, however, the Trump tax cuts enacted in 2017 sparked a major economic expansion that was only slowed by the COVID-19 pandemic in 2020. The BBB that recently passed the House and is now being debated in the Senate extends the lowered 2017 tax rates, while ending taxes on overtime and tips.

And Republicans were quick to point to CBO’s lengthy history of mistaken projections.

House Budget Committee Chairman Jodey Arrington (R-Texas), one of the most vocal congressional advocates for CBO reforms, told The Washington Stand in a lengthy statement that the new scoring is the latest of examples in which CBO, and the Joint Tax Committee (JCT) that assisted in the analysis, “have been consistently wrong on the economic impact of tax and other pro-growth policies.”

Arrington continued, noting that “during President Trump’s first term, CBO projected growth of 2%, whereas actual growth reached 2.7% due to pro-growth policies like the [2017 tax cut] … and now, the JCT is projecting only $103 billion in additional revenue over 10 years from the tax provisions in the BBB. As a result, CBO claims — implausibly — that the largest tax and spending cuts in U.S. history, along with other pro-growth policies, will increase growth by a meager 0.04%.”

The Texas representative added that he believes the BBB, combined with Trump’s “massive deregulation efforts, will unlock tremendous economic growth, get people back to work, and generate record revenue to the U.S. Treasury. As a result of this growth and historic spending reforms, the BBB will effectively be deficit-neutral, and, when considering revenues generated from tariffs and discretionary savings, Republicans will add well over a trillion dollars in future savings.”

The CBO prediction of a growth rate of 0.04% is “absurd,” he said.