The family of Sen. Paul Wellstone asked Vice President Dick Cheney to stay away, so Health and Human Services Secretary Tommy Thompson and the White House's chief congressional liaison were leading an administration delegation to Tuesday night's memorial service.

White House press secretary Ari Fleischer said Cheney offered to attend the service for Wellstone, his wife, his daughter and three campaign aides -- all killed in a plane crash Friday. "The family was appreciative of the offer by the vice president to attend." But he added that it would be inappropriate to characterize the private conversations that ultimately led to the decision that Cheney would not go.

The pilot and copilot also died in the crash in Minnesota.

Another White House official said privately that with the memorial service expected to draw thousands, the Wellstone family told the White House they did not want mourners subjected to the kind of security screenings that Cheney's attendance would have required. This official also said White House advisers worried that the memorial service, with unions bringing supporters by the busload, would double as a Democrat get-out-the-vote rally and be awkward for Cheney.

There was never any thought of President Bush attending Wellstone's memorial, said the official, who discussed the matter only on grounds of anonymity.

But at a signing ceremony Tuesday for legislation overhauling the election system, Bush paid tribute to Wellstone and led his audience in observing a moment of silence.

"I would like to pause and remember a devoted public servant who was taken from us last Friday, along with his wife and his daughter and several other Americans," Bush said.

"Paul Wellstone was a deeply principled and good-hearted man," he said. "He'll be missed by all who knew him and all who had the privilege of serving with him."

Bush, who campaigned in Minnesota for Wellstone's Republican opponent, Norm Coleman, just one week before the plane crash, will go ahead with plans to appear in Minnesota once more for Coleman on Sunday.

Former Vice President Walter Mondale, a Democrat, is expected to take Wellstone's place on the ballot in this final week before Election Day. With control of the Senate hinging on the swing of just one seat, senior Republicans said an early internal poll showed a Coleman-Mondale race would be very tight.