He called Vice President Cheney "indispensable and very debonair." The vice president called him "one of the great Americans of our generation." Standing before an enormous American flag and balloons, the two white-haired politicians wrapped their arms around each other.

The good feeling at a campaign rally Friday between Cheney and the maverick Republican senator from Arizona, John McCain, was palpable It was particularly striking, because it was a few miles from here, in East Lansing, that McCain had unleashed some of his most stinging attacks on George W. Bush just before beating him in the 2000 Michigan GOP primary.

There was no hint of those old antagonisms on Friday, as McCain cemented his singular role in the Bush-Cheney '04 campaign, giving testimonials for the ticket in parts of the country where his popularity is high.

McCain is the only Republican in Congress so far who has accompanied President Bush or Cheney to a campaign event outside his or her home turf. Even Senate Majority Leader Bill Frist (Tenn.) and one of Bush's closest friends in Congress, Rep. Rob Portman (Ohio), have traveled only to Bush-Cheney '04 fundraisers, not rallies.

In Lansing, McCain gave a lengthy introduction of Cheney, calling him "one of the most capable, experienced, intelligent and steady vice presidents this country has ever had." Adopting one of the central selling points of the Bush campaign, McCain said that Cheney "is, in effect, deputy commander in chief in the greatest test of our generation . . . this long, tough fight to vanquish international terrorism."

Cheney reciprocated the flattery. He called the senator, whom he has known for 22 years since McCain was elected to the House while Cheney was a Wyoming congressman, "a distinguished Navy pilot" and "one of the great Americans of our time."

Cheney's remarks before cheering crowds in Lansing and, later in Waterloo, Iowa, touched on the campaign's themes, national security and the economy, as he sought to portray Democratic presidential candidate Sen. John F. Kerry (Mass.) and his running mate, Sen. John Edwards (N.C.), as "leaders who shift with the political winds." Cheney gave his remarks a religious flavor, emphasizing the administration's efforts to increase federal funding of social services by religious groups and its antiabortion stance.

McCain's appearance with the vice president came a month after he shared a stage with Bush in the Pacific Northwest. That appearance ended any lingering hopes by some Democrats that McCain might accept the second spot on a bipartisan ticket with Kerry.

This week, Bush-Cheney '04 aides and a spokesman for McCain said the campaign is scheduling appearances for the senator in coming weeks.

Still, McCain remains a fickle -- and occasionally problematic -- ally. He continues to add to the lengthy list of policy issues on which he openly disagrees with the Bush administration. During the past 31/2 years, these have included tax cuts, protections for patients in managed-care plans and the number of U.S. troops needed in Iraq.

This week, McCain broke with the administration again on an issue of great symbolic importance to Bush's conservative base: whether same-sex marriages should be legal. The Arizonan was one of six GOP senators who voted against a proposed constitutional amendment aggressively supported by Bush that would have prohibited such marriages. McCain called the measure "antithetical in every way to the core philosophy of Republicans" because it interfered with states' rights.

McCain's name has also been used in speculation -- vehemently denied by the campaign -- that Cheney could be dropped from the ticket. Former senator Alfonse M. D'Amato (R-N.Y.) said this month that Bush would improve his chances of reelection with a different running mate, and he proposed substituting McCain or Secretary of State Colin L. Powell.

Kerry campaign spokesman Phil Singer, taking a jab at the vice president's tour, said in a reference to Democrats' criticism of Bush's economic policies: "Dick Cheney finally found a job he's willing to work to save. His own."

With polls showing the race between Bush and Kerry close, the Bush-Cheney campaign is eager to employ McCain's popularity among some independent and Democratic voters. Cheney's popularity with voters is at a low point -- a 22 percent favorable rating in a CBS News/New York Times poll last month. Still, a new survey of Republicans by the National Annenberg Election Survey found that two-thirds of those surveyed said Bush should retain Cheney as his running mate.

The rally in Michigan's capital was the first stop along Cheney's second overnight swing of this campaign. Like his first tour, during the July 4 weekend, this one is taking him through the Midwest. In addition to his rallies Friday in Lansing and Waterloo, he is to attend one in Minneapolis early Saturday. Bush narrowly lost Michigan, Iowa and Minnesota in 2000 to Vice President Al Gore, as well as the counties the campaign selected for this tour.

For his part, McCain, who traveled with Cheney only as far as Lansing, took subtle digs at Edwards. Without mentioning the Democrat by name, McCain implicitly contrasted Edwards's one term in the Senate with Cheney's long government career. Alluding to Edwards's reputation as a sexy politician, McCain said of Cheney, "In short, he is not just another pretty face."

Sen. John McCain (R-Ariz.), left, greets Vice President Cheney during campaign stop in Lansing, Mich.