Except for an ad featuring Mayor Rendell, which has been running in two nearly identical forms for a week, Street has been unable to strut out the kind of endorsements that would make liberals, especially white liberals, overcome the discomfort that some are said to feel about him.

Despite major achievements during 19 years in City Council, including seven as Council president, Street has accumulated baggage.

Endorsements by such mainstream papers as The Inquirer and Daily News would tend to grant permission to uneasy voters to vote for him. But he failed to get either endorsement, just as he failed to get the endorsement of some black leaders, including John White Jr., a defeated rival from the Democratic primary.

So he was left with no option in one of his final two ads but to rely on only one endorsement - Rendell's - and to try in the other to contrast his long record in government with Republican Sam Katz's lack of such a record - beyond a three-year stint on the Board of Education in the early 1980s.

"Where's Sam Katz been these last 19 years, while John F. Street was cutting the budget 15 percent, saving Philadelphia from fiscal collapse," begins the announcer, as the camera zooms in on an empty chair behind the nameplate "Sam Katz."

"He did good things as City Council president, and we need for people to consider that," said David Axelrod, who produces Street's ads.

Interestingly, Street's ads do not mention any of the issues - except experience - on which he attacked Katz during the campaign. The wage tax is not mentioned; school vouchers are not mentioned. Not even the Republican Party is mentioned.

That would suggest polls are showing that none of it has been very effective. The issue in this election is John Street - do you like him or don't you? And by highlighting government experience in the last ad, he is highlighting one clear point in his favor.

Thus, the final line on the final commercial on behalf of Street says almost beseechingly: "If experience, commitment and leadership count, John F. Street, Democrat for mayor."

Katz's last two ads, on the other hand, suggest a candidate with the confidence to reach beyond his natural constituency and into what should be Street's base.

Normally, candidates in the final days of a campaign seek to appeal to their greatest strength, making sure the voters on whom they can count will actually vote.

But one of Katz's last ads is geared directly toward labor - particularly the building trades unions - a bloc that Republicans seldom attract.

The ad, called "Joe," features a white man wearing a hardhat who is identified as Joe Neher of the carpenters union.

"Let me tell you about Sam Katz's record for working people," he says. "Thousands of us in the building trades worked for more than two years building the First Union Center because Sam Katz helped get private money for that . . . If there's one candidate in this race who really knows how to create jobs, it's Sam Katz."

The ad continues with a number of man-in-the-street endorsements, and ends with a black woman saying enthusiastically, "I'm voting for Sam Katz."

"He is trying to demonstrate one of the characteristics a Republican would have to have in a Democratic town," said Kathleen Hall Jamieson, dean of the Annenberg School of Communication at the University of Pennsylvania and an expert on campaign advertising. "He is reaching out to a constituency and guaranteeing that it would not be disadvantaged by his election."

The other ad, a primer on how to use the voting machine, starts by saying, "Regardless of your party, you can vote for Sam Katz."

Then it instructs watchers on how to find lever number 17 - Katz's lever - and six different times it shows the lever being pushed down.

"We're trying to explain to people how to do something that some Democrats haven't done before," said Neil Oxman, who produces Katz's ads.