(CNN) When he first ran for president, Donald Trump blasted the Obama administration for hurting senior citizens by slashing billions from Medicare.

Now, the tables have turned. Democrats are piling on Trump, accusing him of breaking his campaign promise not to touch the federal health care program for the elderly.

The Trump administration unveiled a budget Monday that would reduce spending in Medicare as well as Medicaid, which provides coverage for low-income Americans, by hundreds of billions of dollars compared to current law.

Former Vice President Joe Biden, who is considering a run for the 2020 Democratic nomination, told a crowd Tuesday that Trump is curtailing spending to pay for the tax cut he gave the super wealthy, a reference to the 2017 GOP tax law.

"Trading Medicare and Medicaid for tax breaks?," he said in a speech before the International Association of Fire Fighters. "How is that going to help the people in this room or most of the people you live with? How is that going to help this country?"

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