Sen. John McCain (R-Ariz.) has arrived at what could be the most maverick and historic moment of his career: stopping the hate and fear that his feverish presidential campaign has fostered, fueled by the inflammatory role of his running mate, as only he can do.

This would be McCain’s most career-sacrificing step and hence the most important leadership role of his life because it would contribute to electing Sen. Barack Obama (D-Ill.) as America’s first black president.

Rather than trying to win the White House at any cost, McCain would achieve greatness by throwing all his energy against an America that does not resemble the one he fought for, was tortured for and has represented in the Senate.

Sen. McCain has less than one month to stop candidate McCain and Sarah Palin from continuing to induce hate and fear against Obama. He can begin by doing what McCain does so well, when he wants to: seeing eye-to-eye, standing toe-to-toe, fiercely calling out, fighting against a wrong that must be righted.

That wrong is today’s prejudice and discrimination and the way that it has coalesced around the McCain/ Palin campaign against “that one.” It is the growing anti-Obama feeling that is not based on policies or vision, but on the racial frenzy that McCain’s mismatched running mate has made much worse.

It has already reached dangerous proportions, glossed over in the digital age because we are watching it on flat-screen televisions or while in cyberspace. If we listened to this on radio, or watched it on black-and-white television, we would all be more frightened, and if we were listening to Mort Sahl, Lenny Bruce or Dick Gregory we would realize that even smart comedians do not think it is funny. Seeing it unfold on color TV or YouTube or laughing at Tina Fey simply has us waiting for the next installment. Humor is a good relief from reality, but we should not ignore the reality.

Just ask the Obama volunteers canvassing in Dumfries, Va., who were told as they backed down the steps of one house, “If I see Obama in my neighborhood, I’ll shoot him.” Or ask the young Obama campaign worker, clipboard in hand, standing on the sidewalk outside Mazza Gallerie in Washington about the nasty comments he received when asking passersby for their support. Or read the many responses to articles criticizing the McCain/Palin ticket and see the printable comments like, “we don’t want a Malcolm X for President,” or the unprintable ones.

On Oct. 10, McCain went face-to-face and toe-to-toe with supporters vocalizing and demonstrating the very prejudice and fear they hold in their hearts. It should have been enough for him to think about what his aspirations have aroused in others. It should have alerted McCain, the student of history, to a lesson he surely understands: that economic strife feeds hate and racial divide.

Many McCain/Palin supporters are piling on additional fears. Especially the people McCain saw, heard and took the microphone from in Minnesota. Especially the people to whom he had to tell that Obama “is a decent person and a person that you do not have to be scared of as president of the United States.”

Is it too late for McCain to stop McCain? Supporters who called Obama an Arab were among the many who have been eating up the McCain/Palin rhetoric. During the debates, McCain and Palin have attempted to woo Jewish and Christian voters by shamelessly quoting the anti-Israel provocations of Mahmoud Ahmadinejad. Yet for those supporters who don’t watch the news or read the newspapers, they have been absorbing Palin’s numerous efforts to associate Obama with post-9/11 terrorist fears. The campaign is using a right-wing practice of historical revisionism, and if candidate McCain isn’t careful, his own illustrious history will be the next topic turned on its head.

It is not too late for McCain to stop McCain. It is not too late for him to educate, and lecture if necessary, Palin and the right wing of the party about the danger of their views and how they are setting America back decades. This could be McCain’s most maverick moment.

Steven L. Katz served as counsel to the Senate Governmental Affairs Committee and as director and senior adviser to then-Comptroller General David Walker.