President Trump signed a sweeping domestic policy bill into law on Friday, cementing a major political victory that was timed to take place during Independence Day celebrations.

Accompanied by a flyover of B2 bombers, the same aircraft used in the recent bombing of Iran, Mr. Trump touted the massive tax cuts included in the bill and downplayed the unpopularity of the legislation in polls and the potential impact of spending cuts.

“The largest spending cut, and yet, you won’t even notice it,” Mr. Trump said while standing with the first lady, Melania Trump, on the balcony of the White House.

“The people are happy, they’re happy,” he added.

Mr. Trump highlighted a list of measures included in the enormous bill he believes are popular, singling out, for example, the expansion of the Child Tax Credit and a reduction in estate taxes. He spoke only in generalities about deep spending cuts to programs like Medicaid and food assistance.

The legislation carries significant risks for the Republican Party. The law is estimated to cause the national debt to balloon by trillions of dollars, and the cuts to Medicaid could leave 11.8 million more people without health insurance by 2034, breaking Mr. Trump's promise earlier this year that he would not “touch” the entitlement.

Democrats in the opposition roundly denounced the bill as a move to slash critical government programs to pay for tax breaks for the wealthiest Americans. They have made it clear that they will attack Mr. Trump and Republican lawmakers for pushing through those and other measures that polls have shown are deeply unpopular.