Washington ? President Bush, grappling with economic problems that threaten to complicate his re-election campaign, heard soothing words Wednesday from economists about the soaring budget deficit. But Federal Reserve Chairman Alan Greenspan warned that “substantial and excessive deficits” could harm the economy.

Bush invited private economists to reassure him — and to try to persuade the country — that the deep tax cuts he engineered are helping create jobs at a time when the unemployment rate is at a nine-year high of 6.4 percent.

The economists, who included two Reagan White House officials, told Bush what he wanted to hear — “how the growth and tax package has had such a very positive impact on the economy,” Commerce Secretary Donald Evans said.

Democrats argued otherwise. “This administration’s economic policy is a failure, a total failure,” said Rep. Dick Gephardt of Missouri, a candidate for the Democratic presidential nomination. “This is about as dismal and poor a performance in economics as I can remember in the history of this country.”

Republicans worry that a sour economy will weaken Bush’s support and undercut his re-election hopes.

The economists summoned to the White House said they saw no short-term harm in the deficits, which the administration projects will soar to a record $455 billion this year and $475 billion next year.

“I think the deficits at this point are having a positive impact,” Martin Feldstein, an economics professor at Harvard University who was an adviser to President Reagan, told reporters after meeting Bush. He said the deficits had to be controlled in the long term.

Princeton University economist Burton Malkiel added: “If there is any time in which one ought to have a deficit, it is a time where there is economic slack and a job market that is not recovering the way we would like to see it recover.”

Greenspan, in testimony to the Senate Banking Committee, cautioned that long-term deficits could be harmful.

“There is no question that if you run substantial and excessive deficits over time you are draining savings from the private sector, and other things equal, you do clearly undercut the growth rate of the economy,” Greenspan said.

He also warned of economic problems the country would face in the next decade when the 75 million baby boomers began retiring, placing enormous demands on Social Security and Medicare.

He said that as the wave of baby boomers started retiring after 2010, the country would be “running into potentially serious troubles” in which the claims on the government benefit programs would require large increases in taxes on the working-age population.

Greenspan also said he believed the level of budget deficits affected interest rates, something members of the Bush administration have challenged.

He also told the panel that he had long believed that using tax cuts to provide short-term stimulus to the economy was not a good idea because it usually took Congress so long to enact the legislation that the cuts arrived after the economy needed them.

Democrats on the banking committee pounced on Greenspan’s remarks to bolster their arguments that the government’s deficits, which they blame on the administration’s tax cuts, will damage the economy.

“We are in the midst of some of the worst economic news we’ve had in a long time, particularly the unemployment numbers. And the administration seems to suggest more tax cuts and it’ll get better. So the Congress has passed more tax cuts and it’s getting worse,” said Sen. Jack Reed, D-R.I.

Deficit questions also confronted Gregory Mankiw, chairman of Bush’s Council of Economic Advisers, in an Internet question and answer session on the White House Web site.

How is a deficit of this size manageable? a questioner from St. Louis asked.

“It is a textbook principle of prudent fiscal policy that deficits are an appropriate response in times of war and recession,” Mankiw responded. He said current deficits, as a percentage of gross domestic product, were about 4.2 percent. “Deficits of this size have been experienced six times in the past 20 years, so the economy can certainly handle them. Under the president’s budget proposals the deficit will shrink over time so they should not present a long-term problem.”