There is a growing consensus that Rick Wagoner needs to be ousted as chief executive of General Motors.

That may be the price of at least $15 billion in federal aid that may come for the automakers this week. Senator Christopher Dodd of Connecticut said on Face the Nation on Sunday that Wagoner would have to "move on."

"If you're really going to restructure this, you've got to bring in a new team to do this," he said.

The president-elect, Barack Obama, appeared to support that view on Meet the Press, calling for an end to "the head-in-the-sand approach to the auto industry."

Replacing Wagoner now won't solve anything immediately. But it would be a powerful signal that the company will need to make radical changes in order to survive. In any case, he has been at the helm far too long. For eight years he has presided over a deep deterioration of the company's business and a plunge in its stock price.

The obvious inside candidate would be G.M.'s president and chief operating officer, Fritz Henderson.

Yet for real change to happen, his successor would have to be an outsider. But who? Here are a few possible candidates for the toughest job in America today:

Jack Welch. A troubled American corporate icon needs an iconic C.E.O. Welch's name is among the most intriguing to be floated in recent days. He obviously has experience running a giant, complex, and partly unionized company. Accepting the challenge would allow him to cement his reputation as the greatest American C.E.O. of our time, a reputation that has taken a bit of a dent as General Electric struggles under his handpicked successor, Jeff Immelt.

Lewis Campbell. The chief executive of Textron also has experience running a manufacturing conglomerate. Like Welch, Campbell is a practitioner of Six Sigma. And Campbell is a former G.M. executive, so the learning curve would not be as steep.

Mark Fields. The president of Ford's Americas division, who earlier helped Mazda with its turnaround, has been seen as a possible Ford C.E.O. someday. But the way things are going, there may not be a Detroit automaker to run in the future, so he could be tempted. And G.M. could hurt a rival at the same time, but such a raid would probably not make Washington happy.

Tim Cook. One of the true American-product success stories has been Apple. That led Thomas Friedman to suggest last month, somewhat mischievously, that Steve Jobs should run G.M. But the Apple exec more appropriate to an automaker would be Cook, Apple's chief operating officer and the logistics and operations mastermind at the company. Think different, think very different.

Carlos Ghosn. The chief of Renault and Nissan is the only rock star in the industry. So why would he risk his gilded reputation as a turnaround whiz with a possible lost cause like G.M. Jeffrey Sonnenfeld, a Yale business school professor, tells the Wall Street Journal that financial incentives may do the trick. Ego might be the clincher to any deal. For there are no other mountains left for Ghosn to climb, at least no automotive ones. He will never run Toyota. If he succeeds in turning around G.M., he would be such a hero that the city of Detroit should consider renaming itself in his honor.

Who do you think should run G.M.?