Washington ? Congressional Republicans say they want to cut federal spending by raiding $45 billion from President Barack Obama’s politically unpopular economic stimulus program. But they won’t be able to get their hands on most of that money.

At most, only about $7 billion of the $814 billion in economic recovery money awarded under the 2009 federal law hasn’t already been spoken for, according to the latest White House estimates. And Republican leaders now acknowledge they would be lucky to identify as much as $5 billion in stimulus-related spending cuts as part of a plan to save taxpayers $2.5 trillion over 10 years.

Where did the money go?

It’s not that all the stimulus money has been spent; it has been committed for specific projects and programs. In the confusing money flow from Washington to the rest of the country, there’s still about $168 billion in stimulus money that has not actually been paid out, according to the administration. But it says nearly all of that money already is tied up in contracts with companies, obligations with states and local governments, promised taxpayer relief and commitments to government programs.

For states, much of that money for Medicaid and education has been worked into budgets, so if Congress took it back it could leave shortfalls, said Raymond Scheppach, executive director of the National Governors Association. “That would be a serious problem, I think, because they’re depending on that money.”

The unspent money remains in the federal pipeline despite Obama’s promise that recovery spending would occur swiftly to stimulate the nation’s economy after Congress approved the program nearly two years ago.

Even the $7 billion the White House says is not yet obligated can’t readily be yanked back by Republicans as savings because, administration officials said, planning is well under way for the projects expected to benefit.

“These remaining dollars include funding for major high-speed rail, clean energy and other infrastructure projects that in many cases have already been awarded and just haven’t been formally put under contract,” said Liz Oxhorn, the White House’s spokeswoman for the economic recovery program. “Rescinding these funds could halt job-creating projects years in the making where preliminary work in some cases is already under way.”

The Republican Study Committee, a group of House conservatives, announced a proposal last month to save the government $2.5 trillion over the next decade. Part of its plan involved pulling back $45 billion in stimulus money.