Behind the Curtain: The hard truths about Trump tax cuts

Why it matters: This truism sits at the very heart of Republicans' fight over a grand budget deal. They're trying to convince their members, and the American public, that you can take in less money (taxes), spend more on defense — and somehow reduce deficits without touching the programs that cost the most.

Washington is a city of magical thinking — both parties practice it. Hence, insane deficits under Presidents Biden, Trump, Obama and Bush. We'll grow our way of it! Even if we never do.

• Washington is not a city of math thinking. It's too inconvenient to apply common-sense arithmetic. Instead, you get wonky "dynamic scoring," "budget windows" and "future growth."
• A true tell: The solution is always in a future that never comes.
• Our favorite new D.C. math: Republicans are backing word and math fog called "current-policy baseline," which allows them to "score" lower taxes as costing nothing. Why? Because they're just extending expiring tax cuts. Make sense? That's the magic of D.C. math.

The Trump/Republican budget plan is no different. It's basically a bet that lowering taxes further will juice so much growth that our math problems will ease or even disappear.

• We walked you through the spending reality in our last column. This is our attempt to explain clinically the reality of the current tax system and how Republicans want to attack it with up to $5 trillion in tax cuts.

Let's start with the indisputable facts:

• Fact 1: Republicans want to cut taxes by a minimum of $4.5 trillion over 10 years (and by a maximum topping $5 trillion). That's mainly extending President Trump's first-term Tax Cuts and Jobs Act of 2017 — which cut income taxes for most American families, and reduced the corporate income tax rate from 35% to 21%.
• Fact 2: Some tax cuts — like encouraging businesses to invest more in equipment and infrastructure — can juice the economy.  That's the beating heart of supply-side tax thought.
• Fact 3: Other tax cuts don't spur growth. Trump wants to exempt tip income and overtime pay from taxation, and loosen a cap on the deductibility of state and local taxes. Those provisions, Axios chief economic correspondent Neil Irwin writes, would shift the tax burden away from specific classes of people (servers, people who put in a lot of overtime, and residents of high-tax states) and leave less room for pro-growth tax cuts.
• Fact 4: Trump has tossed tariffs into the mix. In his mind, big tariffs mean other nations will pay the cost of running the U.S. government. Business leaders, mainstream economists and many Republican lawmakers view them as destructive to growth, and ultimately borne by U.S. businesses and consumers. The reason: Higher tariffs typically result in higher costs. If foreign aluminum costs 20% more, someone has to eat the costs — either the company, or you.
• Fact 5: Trump offers conflicting guidance on what he wants in terms of taxes — and any cuts to pay for all of this. He talks of returning more savings to people with tax rebates ... balancing the budget (a mathematical impossibility absent gutting social programs) ... and never touching those actual social programs.
• Fact 6: You could solve the deficit problem by raising taxes enough to erase it. Republicans hate the idea. But Democrats have long held that higher taxes on rich people and corporations could help wipe out deficits without touching social programs. No shot of that in this Congress. But it's an option!

The big picture: That's why the tax fight could consume Congress for all of 2025. It's truly epic in scale and complexity. As TD Cowen policy expert Chris Krueger puts it: A behemoth tax bill is impossible — yet inevitable.

• If Republicans fail to move a bill, taxes on American families will rise back to their 2017 levels next year — something every elected Republican views as unacceptable.
• Figuring out the details, and passing them through narrow congressional majorities, is the hard part. Democrats are likely to vote in lockstep against the legislation, seeing it as primarily benefiting the very wealthy. If the legislation is paired with Medicaid cuts, as House Republicans envision, that would further energize Democratic opposition.

How taxes work: The IRS collects around $5 trillion in annual taxes from over 200 million taxpayers. Filers who make less than $50,000 pay little to nothing in income taxes after credits and exemptions.

• The difference between what we spend and what we take in = our annual deficit. Total annual deficits rolled together over time = total debt ($36.2 trillion today).

Republicans have long argued tax cuts juice the economy with growth, creating more taxable income and wealth. Some do; some don't.

• But keep in mind: Since Trump signed his 2017 taxes into law, deficits are up 248%! So any growth they helped achieve has been swamped by spending. Hence, America's financial jam.
• The deficit is now running about 7% of GDP — roughly triple the economy's growth rate. Every year that continues, the government will be in a deeper financial hole.

The bottom line: Senate Republicans privately predict they'll punt on taxes for a bit and instead ... spend more. They want $340 billion in increased spending for defense border security and deportation efforts, TD Cowen's Krueger writes in his Washington Research Group newsletter.

• How will they pay for that? Tax cuts and spending cuts. When? Later!

Axios' Neil Irwin contributed reporting.

• Go deeper: "The four-way tug-of-war that explains Republicans' tax challenge," by Axios' Neil Irwin.