Updated

A nonpartisan study is casting new doubt on President Obama's campaign pledge not to raise taxes on the middle class.

The Senate health care bill crucial to saving President Obama's signature domestic initiative will hit the wallets of a quarter of all Americans making less than $200,000 per year, according to an analysis by the nonpartisan Joint Tax Committee that assessed the way the bill would hit taxpayers directly through new taxes and fees and indirectly through taxes levied on health care providers and passed on to consumers.

The committee also determined that the bill would subsidized insurance premiums for 7 percent of taxpayers -- about 13 million people -- while some 73 million people would face higher costs from the new fees and taxes.

The potential tax increases in the bill could pose significant problems for the president as he makes his final push for health care reform because he promised to protect middle-class Americans from any tax hikes. Republicans already are pouncing on the committee's analysis.

"For every family that gets some benefit from this program, in other words, a premium subsidy, three families are going to get a tax increase and those three families obviously include the bulk of people you'd call middle class America," Sen. Chuck Grassley, R-Iowa, told Fox News.

More On This...

Democratic leaders are scrambling to gather enough votes to pass the bill in the House later this month so that changes House members want can be added in the Senate through reconciliation, an unusual tactic that allows a simple majority in the Senate to counteract a filibuster by the minority. The steps are part of Obama's final push to pass a comprehensive health care reform bill.

The analysis comes as the Congressional Budget Office updated its cost tally of the Senate bill, estimating that the last-minute changes made to the bill before it was passed Christmas Eve upped the price to $875 billion, from $871 billion. The CBO also estimates that the bill would reduce the federal deficit by $118 billion over a 10 year period, revised down from $132 billion.

But the projection could be undermined by future spending needed to administer parts of the bill, including up to $10 billion for the IRS, up to $20 billion for Health and Human Services and up to $50 billion for "grant programs and other provisions."

The new analysis highlighting the tax burdens of the Senate bill could undercut the president's push.

There's a long list of taxes in the Senate bill, including some paid directly by consumers. Other taxes are on providers who will simply pass it on to consumers.

"It has imposed a lot of taxes and fees on the drug companies, on the medical device manufacturers, on the insurance companies," said economist Doug Holtz Eakin. "All of that is going to show up in higher sticker prices for those that have health insurance."

And then there is the proposed tax on high-cost insurance plans, which was pushed back but will result in significantly higher tax payments by tens of millions of Americans who have generous insurance plans through their workplace.

Also, there would be a brand new Medicare tax on dividends and capital gains, which haven't been taxed before.

Fox News' Jim Angle and Major Garrett contributed to this report.