President Bush sat in a chilly downpour with his parents at the opening of the William J. Clinton Presidential Library, grinned as he chatted animatedly with Sen. Hillary Rodham Clinton (D-N.Y.) during a musical interlude by Bono, and told the shivering audience that President Bill Clinton had "showed himself to be much more than a good politician."

"The whole nation witnessed his brilliance and mastery of detail, his persuasive power, and his persistence," Bush said.

Bush, the father of 22-year-old twins, patted Chelsea Clinton's back several times while her parents were buried under their umbrellas. In his six-minute remarks, he said, "Perhaps the Clintons' greatest achievement is their daughter."

Bush's father, who lost his reelection bid to Clinton in 1992, had spoken minutes earlier of the "inescapable bond that binds together all who have lived in the White House." In a reflection of that connection and an apparent grudging respect between the families, Clinton in 1997 had effusively praised President George H.W. Bush at the opening of his library in College Station, Tex., and the current president welcomed the Clintons to the White House in June for a gala unveiling of their portraits.

Besides, aides said President Bush was feeling gracious. He had just joined Clinton as a second-termer, and many family friends and aides believe Bush's victory helped avenge his father's loss a dozen years earlier.

Bush, in remarks before a luncheon toast, noted that Clinton was "the first in his party to win reelection since Franklin Roosevelt."

Clinton reciprocated the generosity, saying that the first time he saw the Texas governor speaking in Iowa, he called a friend and said, "My God, that guy can beat us."

Before the festivities, Bush and Clinton talked beside a presidential limousine that is an exhibit in the lobby. To "Hail to the Chief," they walked side by side to the stage, with Bush's father trailing and giving his son a clap on the back when they all stopped.

"Shortly before leaving office," the president said as a military aide held an umbrella, "President Clinton said, 'Christ admonished us that our lives will be judged by how we do unto the least of our neighbors.' Throughout his career, Bill Clinton has done his best to live up to that standard."

Clinton aides said they were pleased the president took an energetic part in the program, flying in for four hours on his way to an international economic summit in Chile, with an overnight stay at his ranch in between. Bush will fly Friday to the Asia-Pacific Economic Cooperation (APEC) forum, which Clinton helped advance as a retreat for heads of state.

At a luncheon after the dedication in a white tent hung with eight chandeliers, Clinton joked about his role in promoting APEC and drew laughter with a gentle reference to all the parts of his legacy that Bush has tried to undo. "It's about the only thing I did that he still has to do," Clinton said.

Bush, who led a toast to Clinton with no glass in hand, called the 42nd president a uniquely American story "of talent recognized early and lifelong friendships and hard work that was rewarded."

Bush had been scheduled to stay for about half an hour at the luncheon of Arkansas trout and chicken with barbecue sauce. But the opening ceremony had ended far behind schedule, and Bush's legendary devotion to punctuality is even more acute when he is heading for his ranch. Moments after the glasses clinked, his limousine was rolling, and reporters were running through the mud to scramble into their vans to try to catch up to him.