Mayor Ed Rendell (File Photo)

The arrival of Labor Day marks the traditional resumption of the political season. It closes out a drowsy summer in which the candidates largely raised money, worked behind the scenes and plotted their attacks.

By Nov. 2, Election Day, Democrat John F. Street and Republican Sam Katz together may have spent an additional $8 million to $10 million on an election that already has cost $15 million.

Philadelphians - and everybody else in the region who watches TV or listens to radio - will be unable to escape the 30-second political ads that will come in ever more frequent waves.

Virtually every day for the next two months, Street and Katz will appear in front of a group somewhere in a city of 1.4 million people. John P. McDermott, a minor-party candidate, also will make appearances here and there.

Two summers ago, seeking to establish himself as an early contender in what would become a crowded field, Republican George Bochetto burst onto TV screens with an ad campaign that promised an anxious Philadelphia that there was "life after Rendell."

Bochetto long ago faded from the political scene. But the question persists: Who will come after Ed Rendell, measured by pollsters as the most popular mayor in modern city history?

Both Street and Katz say they can build on the Rendell administration's accomplishments: fiscal stability, better city services and more optimism about the city's future.

Street, 55, of North Philadelphia, was City Council president during seven of the eight years Rendell held office. He will portray himself as the co-author of Rendell's accomplishments, and as the only candidate in November who was ever elected to public office, who ever tamed a budget, who ever wrestled with legislation.

"Almost everything in this city is better today than it was several years ago," Street said in an interview. "People will have to wildly speculate what Sam will do if he were elected mayor. He has no record. I have a record."

Katz, 49, of West Mount Airy, has been a government financial consultant for a quarter-century, specializing in public-private partnerships such as sports arenas. He says that his experience in building a business with $27 million in yearly revenue qualifies him to help Philadelphia achieve what it needs most: economic growth.

"I feel that my understanding of the city is comprehensive," Katz said.

In a reference to Street, he added, "Only somebody who spent their entire career in politics could be persuaded that somebody who spent his entire career in business isn't qualified to lead the city."

McDermott, 49, of the Far Northeast, is the Constitutional Party candidate. A consultant in life insurance and estate planning, he became a surprise third entry Aug. 2 when he filed petitions at City Hall containing well more than the 3,000 signatures needed to get on the ballot.

He calls himself the blue-collar alternative to the major-party candidates, both of whom he said were "too far to the left."

Street, as an experienced, well-known Democrat in a Democratic town, heads into the home stretch as the favorite.

Of the city's 981,000 registered voters, 187,000 are Republicans and 734,000 are Democrats.

No Republican has been elected mayor since Barney Samuel in 1947. Only two - Arlen Specter in 1967 and Frank Rizzo in 1987 - have even come close.

"There are some people in this town who feel their arm will fall off if they pull the Republican lever," said Michael P. Meehan, leader of the local GOP.

But Katz, a moderate who got campaign experience in primary runs for mayor in 1991 and for governor in 1994, expects to draw many Democratic votes. He hopes to match his Democratic foe dollar-for-dollar in campaign spending, a rare feat for any local Republican.

Local political history suggests that a majority of blacks will vote for Street, who is black, and that a majority of whites will vote for Katz, who is white. Pollsters predict about 55 percent of voters on Nov. 2 will be white.

Former U.S. Rep. Lucien Blackwell, a Street ally who ran for mayor in 1991, predicted many Philadelphians would be surprised by how many white votes Street gets.

"We know that most African Americans are not going to get 100 percent of the Caucasian vote," he said, "but I believe Street will set a record in the [white] vote he gets."

Katz, a former Democrat who lives in an integrated neighborhood, predicted he would get a surprising number of black votes.

"There are a group of people who are undecided about this race," he said. "They have known that one of the candidates is white and one is black. But that is not how they are going to make their decision."

Indeed, the campaign itself may be the deciding factor in the election. Street and Katz will be under a microscope, and the man who demonstrates greater leadership may hold the trump card.

This is the most closely watched election in America in 1999, a political off-year in which the only other action of note are governor's races in three small Southern states.

Republicans will hold their national convention in Philadelphia in July, and they would love the country to see that Philadelphia had joined New York and Los Angeles as big cities that cast off their Democratic ways.

The Democrats are just as eager to hold onto power. Joe Andrew, the national party chairman, came to town in late July to announce that the party would "target" Street with about $250,000 in contributions and other aid, such as polling and consulting help.

For much of the summer, Katz has sought to capture attention. He started TV commercials 14 weeks before the election. He held news conferences in which he called for the sale of the Philadelphia Gas Works and promised that he would establish a city office of child care.

But Street was in no hurry. His campaign team, he noted, was tired after a brutal Democratic primary in which he fended off four serious challengers. Katz had no primary foe.

It is also customary strategy for a front-runner to lie low, minimizing the chance of gaffes.

Some in politics believe that Street frittered away a chance over the summer to clinch the election.

"After the primary, I thought [Katz] didn't have any chance," said Elliot Curson, a political and advertising consultant who has backed both Republicans and Democrats. "I do feel he has a chance now. From what I see and hear on the street, John Street hasn't put it away."

But that kind of talk is familiar to Street. Since the first mayoral polls more than two years ago, he has been the consistent front-runner. He believes he has been perpetually underrated by the political class.

Last winter, he said, he heard the same complaints as now - that he was slow to organize his campaign team, slow to declare his candidacy, slow to raise money.

"They said, 'He's not going to work the cocktail circuit,' 'He won't get out and campaign,' " Street said.

In the end, Street did all that. He got 36.1 percent of the vote in a Democratic primary with five serious contenders and one fringe candidate. He topped his closest rival, Marty Weinberg, by 5.3 points.

On issues, the debate between Street and Katz should be intelligent and well-informed.

Street so far has promised to expand city day-care services. He has said he would float bonds to pay for demolishing the city's abandoned houses and commercial buildings, and to supplement city police with an auxiliary force.

Katz favors major reform in the city's public schools, and Republicans have pledged to support a ballot question that asks voters to change the city charter to make school board members' terms concurrent with the mayor's term. As it stands, the new mayor will have to live with a board appointed by his predecessors.

School vouchers and the wage tax are two issues on which the candidates disagree.

Street opposes vouchers as a raid on tax money required for public schools. He has said that the main problem facing city schools is a severe shortage of money.

Katz, who served on the school board in the early 1980s, advocates private-school vouchers as a way to keep parents of school-age children from leaving the city.

On the wage tax, Street has committed himself to carrying out the city's five-year plan, which calls for reducing the rate for city residents to 4.45 percent by 2004. The rate was 4.96 at its peak. Street says he would reduce it more "if possible." But a steep reduction, he said, would be irresponsible and would mean cuts in city services.

Katz has said he would seek to lower the wage tax much more than now planned, but he said he would wait until later to say how much more. The tax, he said, was a major reason that 130,000 people have left the city since 1991.

At least two televised debates will be held during the campaign. McDermott, who is strongly anti-abortion, hopes these will give him a chance to explain his proposals to divide the public school system into seven districts and to reduce City Council from 17 to seven members. He said he had not yet received invitations to debate.

So, with Labor Day, the race begins.

Thaddeus Mathis, a professor at the Temple University School of Social Administration, said he believed that voters were a little worried about who would follow Rendell.

"I suspect there is some general anxiety," he said. "People tend to be anxious about any change."