I'm a huge Ford critic, but let me play devil's advocate for a minute and try to offer a defense of the mayor - the way I believe he would defend himself if he was willing to speak publicly:
Let's assume Ford does crack. He's probably not the only high ranking official in public or private office who engages in recreational drug use. The only difference is that those people don't have reporters peaking at them from behind bushes or willing to meet drug dealers in dark alleyways on the promise of incriminating evidence. Everyone has their flaws, but as long as they don't have the country's biggest newspaper on an all out campaign to smear them, those flaws usually stay hidden. The fact is, if Ford is doing a good job (which he and his allies believe strongly), then it doesn't really matter what he chooses to do in his private time. In fact, it is because Ford has been so effective in derailing the gravy train and taking power away from the elites in the city, that he has been persecuted so strongly by the left-wing media. They may have finally found some unrelated issue that could be used to drive him out of office and effectively shut down his campaign to reduce government waste and cut taxes.
This is how I think Ford justifies his choice to simply ignore the issue. He knows they've caught him doing something illegal, but he is refusing to let that put an end to his political mission.
Again, let me emphasize that this is my attempt to understand Ford and explain his behavior since this story broke, not an attempt to sympathize with him or excuse him. I think Ford overestimates the extent to which he alone is being targeted by the media (if other public figures are as personally flawed as him, they are much better at hiding it or at least addressing it publicly). He overestimates his personal importance to the conservative movement (he would help the movement if he just resigned and let someone more capable take over). He really mischaracterizes the extent to which all of his political opponents are somehow allied against him, or that in criticizing him and his behavior they are necessarily opposing/supporting any particular political position. And, most importantly, he totally underestimates the seriousness and public importance of his personal flaws - from illegal drugs to marginally corrupt political behavior to his driving habits.