Over and over, President Bush has proclaimed fierce loyalty to Dick Cheney as his running mate for a second term but questions stubbornly linger about whether the vice president will remain on the Republican ticket.

Cheney's approval ratings have plummeted amid persistent questions about his role in promoting the Iraq war and in handling the Sept. 11 terror attacks.

Some prominent Republicans grumble — in private — about Cheney's behavior and his dominant role in administration decision-making. There also is unease in GOP circles about comparisons between the youthful, energetic John Edwards (search), the Democratic vice presidential candidate, and Cheney, a veteran of decades of political wars who seems uncomfortable on the campaign trail.

Former Sen. Alfonse D'Amato (search) of New York, the only prominent Republican to speak publicly about replacing Cheney, said that "I believe the president can guarantee his essential re-election by looking to several other notable individuals who would add a great dimension to his ticket as a running mate." D'Amato suggested Secretary of State Colin Powell or Arizona Sen. John McCain (search).

McCain scoffs at the idea. "I think the day that President Bush drops Vice President Cheney will be a cold day in Gila Bend, Arizona," he said. "I see no scenario in which the president would replace Dick Cheney."

Bush gave a terse answer to the question about how Edwards would stack up against Cheney. "Dick Cheney can be president. Next?" Bush snapped. The White House insists that Bush is sticking with Cheney.

While no one in the GOP establishment suggests there's much chance that Bush would dump Cheney, there is still a lot of "what if" talk as the political conventions near.

What if, for instance, Cheney comes to believe that he's become a burden on the ticket and withdraws — perhaps citing health reasons. Few would question his motives under such circumstances.

Cheney, 63, has had four heart attacks since 1978, the most recent in November 2000 right after one of the closest, most stressful elections in U.S. history. A sophisticated pacemaker-defibrillator was placed in his chest in June 2001. The vice president had his annual heart checkup in May and was told there were no signs of irregularities or blockage in blood flow.

What if, the speculation goes, Bush decides — or is persuaded — that jettisoning Cheney is his only chance of being re-elected. Again, almost everyone close to the president suggests such an initiative would have to come from Cheney himself.

Cheney is championed by the party's conservative base, and anything seen as a move to displace him could anger the political right that Bush has worked so hard to court.

"One of Bush's strengths is that he sticks to his guns. He would appear both weak and political to dump Dick Cheney, and he's not going to do that," said Charles Black, a Republican adviser who is close to the White House. "It's not the way he operates. Plus, Cheney is very important to the president and to the government, regardless of politics."

But a Cheney departure still remains a wild card in the presidential sweepstakes, for health reasons or otherwise.

Political consultants and analysts generally agree that vice presidential candidates usually have little bearing on the outcome of an election, that the focus is almost entirely on the party standard bearer.

But Cheney isn't just any vice president.

He has been the gray eminence of the Bush presidency, the veteran political operative, serving almost as a virtual prime minister.

Jokes abounded early on about how Cheney, not Bush, was pulling the strings of power. According to Bob Woodward's new book, it is still Cheney's voice that Bush listens to most.

Bush only agreed to testify to the Sept. 11 commission this spring if Cheney could be by his side.

"I think that Cheney has almost been surgically grafted to the president," said Ross Baker, a political science professor at Rutgers University. "He enjoys the trust of the president, he is virtually a member of the Bush family, and I can imagine almost anybody being pushed overboard sooner than Cheney, starting with (Defense Secretary Donald) Rumsfeld."

"Cheney may jump, but he won't be pushed," Baker added.

Public attitudes have changed toward Cheney since he joined Bush's ticket in 2000 as a soft-spoken, avuncular presence.

An Associated Press-Ipsos poll from early June found that 51 percent of Americans want to keep Cheney on the ticket and 43 percent want Bush to pick someone else.

Perhaps more significantly, 28 percent of GOP voters surveyed — almost three in ten — thought Bush should pick someone other than Cheney as his running mate.

Generally, groups that most preferred to get rid of Cheney were women (46 percent), non-whites (51 percent), those who live in cities (48 percent), and Democrats and independents (both 53 percent), according to the Associated Press-Ipsos poll of 788 registered voters taken June 7-9.

The poll has a margin of sampling error of plus or minus 3.5 percentage points. The error margin is slightly larger for subgroups.