President Bush, sensing political momentum for the first time in more than a year, flew here Wednesday night prepared to accept his party's nomination and to offer an agenda for a second term and a strong defense of his war on terrorism.

His speech will range from plans for restructuring the nation's intelligence services, to new ways to help the uninsured obtain health coverage, to a call for Congress to change labor laws to give workers more flexibility in using overtime hours at their family's convenience. Democrats call the flextime plan a way for employers to avoid paying overtime.

Bush's agenda consists almost entirely of expanded or repackaged ideas he has promoted before -- partly because the deficit precludes major new programs. Outside economists said campaign strategists argued this week that the political terrain has shifted dramatically in the president's favor and that specific proposals are unnecessary.

"The strategists are saying, 'Everything is breaking our way. It's looks like it's almost over,' " said one close adviser who demanded anonymity. In this climate, the political strategists believe they have no reason to offer plans that would give opponents new targets to attack.

"As long as he can win by talking about how great America is and blah, blah, blah, why take a chance?" said Bruce Bartlett, a conservative economist with the National Center for Policy Analysis. "All we're going to get is pabulum."

Republican lawmakers and consultants have fretted for months that Bush has hurt himself by waiting too long to unveil his plans, and that he should have been reaching out to swing voters for months instead of focusing almost exclusively on revving up his base supporters. Bush was still making choices and ordering his staff to do more work on his second-term agenda in the week leading up to the Republican National Convention.

The prime-time address, which is scheduled to last about 50 minutes , will try to characterize the invasion of Iraq as an essential step toward bringing democracy to the Middle East. Bush's speeches during his week-long tour of swing states en route to New York included frequent references to the "transformational" power of liberty, and aides said he will use that rubric to explain his domestic and foreign agendas.

Aides said Bush's address will seek to appeal to supporters who fell away as the war dragged on and casualties mounted. The president hopes to reclaim some of that support by devoting part of his speech to describing himself and how he makes decisions. Advisers said Bush will describe much of his record and intentions as "reforming and adapting government," including creating the Homeland Security Department and enacting a prescription drug benefit for Medicare.

"We're the incumbent party running on an agenda of change. Here's what we want to do: We need to do these reforms. We need to change the government. We need to make it adapt," said Matthew Dowd, the Bush-Cheney campaign's chief strategist.

The agenda will in some ways highlight the president's vulnerabilities. The Gallup Organization reported this week that Bush's approval rating on education is the lowest since he took office. Advisers said Bush plans to call for new accountability for high schools and for improved math and science instruction. The plan is a successor to the No Child Left Behind Act, which the president pushed through Congress and is now unpopular with many educators.

The most politically risky part of Bush's remarks will be what aides described as an emphatic pledge to pursue his costly plan to alter Social Security to allow younger workers to invest a portion of their payroll taxes in stocks and bonds, while leaving untouched the Social Security benefits of retirees and those near retirement. The Social Security initiative will be cast as part of Bush's plan for an "ownership society," which envisions using tax incentives to encourage the purchase of homes, private health insurance policies and personal investments.

Bush will also call for a simpler tax code but, as with the revamping of Social Security, will not say how he wants it done, according to the aides. Many conservative economists have pushed the campaign to unveil detailed proposals for Social Security and the tax code, saying that Bush will need a mandate from voters to enact such contentious policy changes.

Rep. Rob Portman (R-Ohio) said Bush made a deliberate decision to wait until he had the nation's full attention and to have fresh ideas to discuss throughout the fall. Congressional committee chairmen, meeting with Bush on the White House Truman Balcony, urged Bush this summer to begin marketing his reelection policies, but the president waved them off. "People were getting nervous," recalled Rep. John A. Boehner (R-Ohio). "He said, 'You don't want it to be stale come mid-October.' "

Aides said Michael Gerson, Bush's chief speechwriter, produced a first draft of the speech two weeks ago, based on an outline that emerged from conversations with Bush. Since then, the speech has been going through intense editing sessions in the White House family theater whenever Bush has been off the campaign trail, with the president reading passages aloud and his staff hashing over cuts and changes. The audience for these sessions typically has included Gerson, former counselor Karen Hughes, national security adviser Condoleezza Rice, communications director Dan Bartlett and a few other officials, the aides said.

One problem for both campaigns is that undecided voters are unlikely to be watching the conventions, so the Bush-Cheney campaign is mobilizing supporters to talk about the convention speech at work, at church and around town. "People will ask a neighbor next door what they thought of it -- that'll be important," Dowd said. "So you don't know what you've accomplished until days after, when people have had a chance to digest it."

Weisman reported from Washington.

President Bush and Laura Bush greet supporters in Columbus, Ohio. His campaign is mobilizing supporters to talk about the convention speech.