New York’s two political giants, Hillary Clinton and Rudy Giuliani, seemed for a moment after November’s election to be moving on parallel tracks toward their respective parties’ Presidential nominations in 2008. If anything, America’s Mayor had the straighter shot, while Mrs. Clinton’s prospective candidacy would have to deal with the legions of Hillary haters in the heartland.

A few weeks later, Senator Clinton is still marching steadily toward the nomination, but Mr. Giuliani’s Presidential hopes are evaporating. If you want to understand why the two politicians are headed in such different directions, it’s worth taking a look at the company they keep, at the contrast between Mrs. Clinton’s broad circle of old political hands and Mr. Giuliani’s tight, loyal cadre.

Mrs. Clinton’s network is broad and largely female, packed with some of the nation’s most experienced political operatives and spanning cities, generations and ethnic groups. They include longtime practitioners of political hardball like Ann Lewis and Harold Ickes, discreet loyalists like fund-raiser Patti Solis Doyle and former aide Maggie Williams, and Democratic Party media stars like James Carville. She can also rely on the advice of one of America’s great political minds: her husband’s. (He held high national office at one point in the recent past.)

But where Mrs. Clinton has, say, Mr. Ickes, Mr. Giuliani has … Bernie Kerik. The former police commissioner’s nomination to the top Homeland Security job blew up into a pile of dirty laundry dating back to the years when Mr. Giuliani was Mayor. The explosion was so immediate and so devastating that some speculated Mr. Giuliani had walked into a trap set by the wily Karl Rove, presumably no fan of the gay-friendly, thrice-married former Mayor. But others were asking: Why didn’t Mr. Giuliani see this coming? Wasit because he trusted Mr. Kerik too much? Why didn’t anyone raise a red flag?

The answer may lie in Mr. Giuliani’s small circle of advisors. They’re men-mostly-who served under him in city government. Some of them date back to his time as United States Attorney. His top aides, Tony Carbonetti and Denny Young, are known for their savvy handling of the city’s tough and peculiar scene. But neither has any real experience in national politics.

Indeed, Mr. Giuliani has shed political advisors, not added them, over the years. For various personal reasons, he’s cut out old aides like Bruce Teitelbaum and Cristyne L. Nicholas. His circle, always opaque, has grown smaller and more isolated in the private sector. The survivors in his private practice are defined above all by one trait: personal loyalty. When the first political storm hit, Mr. Giuliani seemed to lose his balance, standing by Mr. Kerik one day, distancing himself from him the next.

Ultimately, it’s never seemed to matter very much who stands beside Mr. Giuliani. Brilliant and instinctually combative, he has steered his own course. So if there are no advisors to purge after the Kerik debacle, its because Mr. Giuliani was relying on the advice of his own most trusted counsel: himself. RudyWorld/HilWorld