Republican tax aides say the vast majority of the benefits Democrats are seeking to preserve are not tax cuts but checks written by the Internal Revenue Service and sent to the working poor. Given the huge increase in government aid, like food stamps and unemployment benefits, letting some assistance lapse makes sense, they say.

N. Gregory Mankiw, a former Bush White House economic aide and an adviser to Mitt Romney, said that a typical family in the lowest 20 percent of the income scale now receives $3 in government benefits for every $1 earned. Even the middle 20 percent receives slightly more in government largess than it pays in taxes, he said.

“What happened to the failed stimulus being ‘targeted, timely and temporary?’ ” asked Antonia Ferrier, a spokeswoman for Senate Finance Committee Republicans. “With our economy as weak as it is, stopping the president’s massive tax increase on nearly a million small businesses and then overhauling our burdensome tax code is how we’ll get America moving again. The same can’t be said for keeping the expanded stimulus spending through the tax code.”