On your TV screen, some big-name Democrats are saying some very good things about John Street.

But in your mailbox, their party is saying some very bad things about Sam Katz.

A mass mailing paid for by the Democratic State Committee features on the outside a giant wrecking ball and a large-type headline: "Destruction." Inside, it trashes Republican mayoral candidate Katz's wage-tax and school-voucher programs.

"Sam Katz Supports Republican Policies That Would Destroy City Finances and Wreck Our Public Schools," the text states, quoting Mayor Rendell saying that Katz's proposal to reduce the city wage tax below 4 percent by 2003 would be "debilitating" to key city services.

A second, similar-themed flier shows a 1950s-era boy with a slingshot hiding a failing report card behind his back, and it says: "Somebody's Got Something to Hide."

There is no mention anywhere in the flier of Street, the Democratic nominee.

"The purpose is remind Democrats to get out and vote and vote Democratic," said Neil Cashman, executive director of the state committee.

Cashman, who declined to say how many voters were getting the mailing or what it cost, said the state party was planning to aid not only Street, but Democrats in Allegheny County and elsewhere.

"They're desperate and that's what desperate people do," Katz campaign director Bob Barnett said. He said the Street campaign has grown progressively negative as the election draws closer. The two are thought to be running neck-and-neck.

Meanwhile, Street is praised in a new TV ad that features some prominent Democrats - District Attorney Lynne Abraham, state Rep. Dwight Evans and state Sen. Allyson Schwartz - all urging fellow Democrats to rally behind the party candidate.

With the election to succeed Rendell now less than two weeks away, both well-financed candidates are stepping up their advertising, even as the familiar messages from the Street and Katz camps remain essentially the same.

Katz did not start any new TV ads yesterday, although his campaign did go on the radio with a spot similar to one that aired last week, saying that Street and his allies have been distorting Katz's tax-cut plan in a negative campaign.

In recent days, the Street campaign has focused almost solely on two things: Calling for Democratic unity in a city where Republicans are outnumbered by a nearly 4-1 ratio, and blasting Katz's tax proposal.

Street also wants to reduce the wage tax, now pegged at 4.61 percent for residents, but only to 4.45 percent in 2003, still higher than the Katz plan.

Ken Smukler, a Democratic consultant who worked for Marty Weinberg in the primary but is not involved in the fall campaign, said Street's strategy is a simple one: To make the entire election about party affiliation.

"The election has always been about whether party trumps race or race trumps party," Smukler said.

That means that if voters stay loyal to the party, Street will clearly win, but if voting is largely along racial lines, Katz will be victorious because there are more whites in Philadelphia than blacks or other racial and ethnic minorities.

That dynamic is one reason why the campaigns have seemed so bland to many, he said, because neither is eager to rile up voters.

Street's newest 30-second TV spot, unlike his earliest ads, doesn't feature Street but is a string of testimonials from Abraham, Schwartz, Evans, and labor and Democratic leader John Dougherty of the electricians' union, each praising Street's experience in public office.

"He has a record, and a history, and experience to make it happen," said Schwartz.

Each of the Democrats in the ad has strong appeal to at least one or more of the groups that have been identified as swing voters: Liberals, Jewish voters, blue-collar Democrats and people living in Northwest or Northeast Philadelphia.