President Obama rolled out his Buffett Rule — named for billionaire investor Warren Buffett — last year, and he later specified that he believed those making more than $1 million a year should pay at least a 30 percent tax rate.
But the AMT now ensnares more middle-class taxpayers and frequently receives a patch from Congress to rein in its reach.
Democrats have also suggested that the rule could be used to reduce deficits and said the idea underscores that they have a more balanced approach to bringing the federal debt in line.
For their part, Republicans, who have long resisted raising taxes on the highest-earning Americans, call the Buffett Rule a political gimmick and say that lawmakers should concentrate on reducing spending.
Whitehouse noted on Tuesday that other studies had found his measure raised more revenue.
The nonpartisan Urban-Brookings Tax Policy Center, for instance, said the plan would raise roughly $114 billion over a decade, though the group also said Whitehouse’s bill would fall far short of offsetting an AMT repeal.
“No matter how you slice it, that’s real money that could help bring down our deficit,” said Whitehouse, whose measure would phase in the Buffett Rule for taxpayers making between $1 million and $2 million a year. “Most important: It’s simply the right thing to do.”
JCT, in its analysis, assumed that a host of current tax provisions would expire, as scheduled, at the end of the year.
If the Bush-era tax cuts expire at year’s end, the top marginal individual tax rate would rise to 39.6 percent, from its current 35 percent.
Capital gains and dividends, which are now taxed at a top rate of 15 percent, would rise to top rates of 20 percent and 39.6 percent, respectively, in 2013.
The Tax Policy Center’s $114 billion estimate is also based on tax provisions expiring as scheduled. The group found that Whitehouse’s proposal would raise $264 billion over a decade if current tax policies were kept in place.
For comparison’s sake, the Congressional Budget Office has said that the president’s budget would tack $6.4 trillion onto deficits over that same time span.
Rep. Paul Ryan (R-Wis.) has said that his new budget would reduce deficits by more than $3 trillion more than the Obama budget.
This post was updated at 8:03 p.m. to include the revised revenue estimate.