Trump’s Tax Proposals Face a Fiscal Reckoning

No tax on tips? Lower corporate taxes? No tax on Social Security benefits?

The slew of tax cuts President-elect Donald J. Trump proposed in loosely defined slogans over the course of his victorious campaign will now face a fiscal reckoning in Washington. While Republicans are poised to control both chambers of Congress, opening a path for Mr. Trump’s plans, the party is now grappling with how far they can take another round of tax cuts.

Mr. Trump’s ambitions for a second term will ultimately have to compete with the signature accomplishment from his first: the giant tax package that Republicans passed and Mr. Trump signed into law in 2017. Large swaths of that tax cut expire at the end of next year, setting up an expensive debate that could overshadow Mr. Trump’s other goals.

“Nobody wants to acknowledge at all the sheer enormity of the challenge,” said Liam Donovan, a Republican strategist. “There’s a reckoning coming.”

Unlike in 2016, when Mr. Trump’s victory surprised many in Washington, Republicans have spent months preparing for their return to power. They have been discussing using a fast-track budget process that skirts the supermajority requirement for legislation in the Senate, a tactic that would allow for a party-line passage of more tax cuts if Republicans ultimately keep control of the House.

But lawmakers and advisers to Mr. Trump are undecided about how much money they can commit to lowering the nation’s taxes again. The cost of just preserving the status quo is steep. The nonpartisan Congressional Budget Office has estimated that continuing all of the expiring provisions would cost roughly $4 trillion over a decade, and Mr. Trump’s campaign proposals could add trillions more to the debt.

In interviews before the election, some Republicans said the party would have to show some fiscal discipline.