During the rare times when fiscal conservatives express unhappiness with the Bush administration, they are almost always referring to the size of the federal budget and the resulting deficit. Recently, however, a left-leaning think tank has rescued them from this lament by demonstrating that the concern may be misplaced, and the administration should not be blamed for spending too much.

The conservative concern over the budget may have begun a couple of years ago with the Republican Study Group, which consists of 100 right-leaning House members who worry about the amount government spends and its reach. Conservative radio and television programs later picked up on the idea that spending was the administration’s bane, and it has affected the presidency since 2004.

But Robert Greenstein of the Center on Budget and Policy Priorities shows that federal spending as a share of the economy remains lower than the average level over the last 30 years, and that increases in domestic spending account for only about 15 percent of the cost of legislation enacted since 2001. The administration may have significantly increased spending on, for instance, education, but that is a small percentage of the total, and is not why the Congressional Budget Office changed its 2002-2011 forecast from a $5.6 trillion surplus to $3.2 trillion in deficits.

Instead, says Mr. Greenstein, “the president’s tax cuts are the single largest factor driving the return of deficits.” By 2010, these tax cuts, he points out, will cost more than three times the federal funding for education – elementary, secondary and post-secondary. They will be worth the cost of the Departments of Education, Veterans Affairs, Homeland Security, Housing and Urban Development, State and Energy combined. The Brookings Institution-Urban Institute for Tax Policy Center shows why: In 2006, the average household with income above $1 million will receive $112,000 from tax cuts enacted since 2001.

President Bush, whose approval rating is in the mid-30s, takes the blame for a lot of problems with the federal government. But thanks to Mr. Greenstein, the president no longer can be blamed for being a spendthrift. Fiscal irresponsibility is an entirely different issue.