With the recent publication of Pat Buchanan's book, A Republic, Not an Empire, where for one he condemns the Nazi threat to the US, there has been much speculation as to why Pitchfork Pat has not been more rigorously attacked by other politicians and the media. As you mentioned, John McCain called for him to leave the GOP (the very possibility of which has sent other Republicans into a tizzy) and Donald Trump, who coincidentally is considering candidacy under the same party banner that Buchanan is now eyeing, referred to his views as "extreme and outrageous."
The book isn't even Buchanan at his most crude. He's certainly been much more extreme and outrageous in the past, indulging in compliments to Adolph Hitler and vague denials of the WWII holocaust, references to "chopsticks" and "porch-niggers", affiliations with Klansmen and other Aryan-type supporters. With all this absurdly bigoted baggage, how can Buchanan be considered a legitimate politician and even, in a statement from the Quayle camp, a "sincere and ... good man"? Why is he not roundly condemned and thrust from the stage of American politics? Obviously he doesn't serve simply as a foil against which the other candidate exhibit their more erudite, progressive ideals. Then why? Is there really any wonder?
Buchanan is a member of the innermost circles of the political and media elite. He may lack the official pedigree of a Bush or a Gore and, oh yes, experience as an elected official, which is apparently not a prerequisite for the presidency anymore anyway. Yes, he's one of them; moreover, his views, to my mind at least, while more strident are hardly so very different from those of the more moderate candidates who tout compassion while executing 100 individuals and instituting workfare programs. In fact, I prefer Buchanan's "sincerity" over that of his more palatable fellow candidates. After all, what is this compassionate conservatism if not a privileged, condescending sniff at the great numbers of people left behind in this current swell of prosperity. The sugar-coating by Bush and his ilk makes him all the more dangerous, allowing supporters to naively congratulate themselves on their own benevolence while upholding the status quo of the elite. Gore and Bradley with their pledges of healthcare and tax breaks are no different. With all the talk of prosperity, statistics show that only the top 20 percent of households have increased their percentage of the spoils. Everyone else is working at a loss. It's easy to see for whom this system, be it ruled by Democrat or Republican, is working.
Nevertheless, let us not underestimate Buchanan by thinking him a minor player or the mad man of the political sphere. He has a frightening appeal and concentrates his efforts on the more vulnerable segments of society, working families desperate to improve their means of survival. This is no fringe dweller. The rhetoric may be harsher, but the goals are the same: the furthering of privilege, American imperial interests and, most of all, capitalism.