After the primary last May, Sam Katz thought he had a chance to be Philadelphia's next mayor. Now, he's sure he does.

At least that's the impression his aides have been working to convey with the campaign due to resume in earnest next week. They've been feeding reporters results from various polls, theirs and others, showing Katz within a few points of John Street.

Regardless of the numbers, Katz has reason to be pleased with his current position and to know that, in trying to become the city's first Republican mayor in a half-century, he has not launched himself on a fool's errand.

For whatever it's worth, he won the summer phase of the mayor's race, largely by default.

Street was all but invisible in June, July and August, working behind the scenes to raise money and plan for the fall. So Katz had the sidewalks and the airwaves to himself.

He used them well, building his self-confidence, his familiarity with neighborhood concerns and voter recognition for both his name and his face.

Unfortunately for Katz, general elections usually aren't decided in the summer. And Democrat Street is still seen as the favorite, even by politicians who think he's squandered his time since the primary.

But Katz's advisers think they enter the fall with a theme that might resonate: the notion that their man has demonstrated that he is better suited to assume the role of civic cheerleader and ubiquitous presence that Ed Rendell has made central to the job of being mayor.

"We're exactly where we want to be," Katz said in an interview this week, "in part because the other guy let us do things, go places, be compared to him in a way that only his inaction would have permitted. There's an echo out there now, 'Where is he? How come he isn't here, too?' "

Katz says he also has made modest inroads among Democrats, black and white, by wooing them more assiduously than Street - who needs significant white Democratic support and a solid black turnout if he is to win.

"Not to be self-delusional but nonetheless, I am hearing things in African American neighborhoods I wouldn't have thought possible," Katz said. "They are not so much 'I'm going to vote for you,' although I hear some of that. It's more, 'Don't assume that you can't get some votes here. Make sure you come out. Make sure you show your interest.' "

He urges campaign audiences throughout the city not to think of this election as black versus white or Republican versus Democrat. That is often the only context in which the word Republican passes his lips. And for good reason.

Party identification is a huge obstacle for him, and not just because the vast majority of Philadelphia voters are Democrats. Even though he used to be a Democrat, his views on at least two key issues are very much in keeping with the national Republican Party - a point Street is sure to make, particularly if the race looks close in October.

Katz talks about cutting taxes (a perennial Republican proposal) as one of the prime ways to stop the city's ongoing population decline. While he has yet to present any specifics, he favors reducing the wage and business rates to levels lower than those included in the current five-year plan, which is backed by Street.

And like many prominent Republicans across the country, Katz favors school choice, both on the merits and the politics. Backing a voucher experiment in Philadelphia, he says, might well generate support for more public school funding from Gov. Ridge, a fellow school-choice advocate and a fellow Republican.

For those positions, Katz can expect to be depicted in some quarters as a partisan, as well as a businessman who has never held elective office and thus knows little of political realities. He will respond by portraying the former City Council president as the embodiment of an inadequate status quo, a man still fighting the last war.

"They [Street and Rendell] did what they needed to get the bond ratings back up in 1992," he said. "That was a problem then. That's not the problem in 2000. The problems now, the ones that make people leave, are public safety, taxes and schools. Those are different, and they're tougher."

State Rep. John Perzel (R., Phila.), who counts votes for a living as majority leader in the state House of Representatives, likes what he sees and what he hears.

"Sam's not threatening to the black community, and he's going to carry the Jewish community," Perzel said after Katz stopped by a neighborhood meeting in Mayfair. "I think he's in the hunt."

So do I.