WASHINGTON -- Democrat Joe Sestak launched his first television advertisement of his general election campaign for Senate on Tuesday, an attack on Republican Pat Toomey that echoed his primary skewering of Sen. Arlen Specter.

But the ad also showed the financial weaknesses of Mr. Sestak's campaign: It's a limited buy that avoids the pricey Philadelphia market and comes only after weeks of ads from Mr. Toomey and outside groups put Mr. Sestak on the defensive.

The ad shows Mr. Toomey in a cable television appearance from 2007 saying, "The solution is to eliminate corporate taxes altogether."

"He's for them, not for us," the ad's announcer intones, continuing the campaign's theme of portraying Mr. Toomey as one who cares more about corporate interests than the middle class.

The Sestak campaign spent about $110,000 to air the ad, which is running in every Pennsylvania television market except Philadelphia, according to sources close to the campaign. It was produced by Philadelphia's The Campaign Group, the same firm behind the spot showing Mr. Specter declaring: "My party switch will enable me to be re-elected."

The ad crystallized Mr. Sestak's argument against the incumbent and helped contribute to his convincing Democratic primary win in May.

In this case, the attack follows the class warfare argument Mr. Sestak, a second-term Congressman and former Navy admiral from the Philadelphia suburbs, has pressed so far in the general election. Mr. Toomey's campaign responded that the ad took his words out of context. Elsewhere in the CNBC segment -- although he doesn't back off his position -- Mr. Toomey acknowledges that an elimination of corporate taxes might be unworkable in Congress and he would still like to see them reduced significantly.

Toomey spokeswoman Nachama Soloveichik said Mr. Toomey thinks a corporate income tax of zero is impractical. "He knows it's not a realistic policy position and more an intellectual policy position than anything else," she said.

"[Mr. Sestak] believes you create jobs by massive government spending, and that's why he voted for the stimulus, and that's why he thought the stimulus should have been even more than it was," Ms. Soloveichik said.

With nine weeks until Election Day, Mr. Toomey finds himself as the front-runner, having held a consistent polling lead for months. A Reuters/Ipsos poll released Tuesday showed Mr. Toomey ahead, 47-37 percent. A Rasmussen Reports poll out Tuesday showed a closer race at 45-39.

The Sestak campaign has tried to paint Mr. Toomey as beholden to Wall Street and big corporations.

Mr. Toomey traded currency swaps and similar derivatives in New York and Hong Kong in the 1980s before moving to Allentown to help run a restaurant chain. After serving in the House of Representatives from 1999 to 2005, Mr. Toomey became head of the Club for Growth, a conservative anti-tax group.

Mr. Toomey, meanwhile, has painted Mr. Sestak as a liberal puppet of the Obama administration and Congressional Democrats -- who have lost popularity in Pennsylvania and nationally -- for backing the stimulus bill and health care reform, among other policies.

"This is ideological trench warfare," said Franklin and Marshall College professor and pollster G. Terry Madonna. "There's no middle here."

Mr. Toomey has had more money to push his message. He ended June with $4.65 million in the bank, as opposed to Mr. Sestak's $2 million, and has been broadcasting ads statewide since early July. He also has gotten a boost from anti-Sestak ads paid for by the U.S. Chamber of Commerce, Crossroads Grassroots Policy Strategies and the Club for Growth.

On Mr. Sestak's behalf, the Democratic Senatorial Campaign Committee launched an ad attacking Mr. Toomey last month, the first serious broadcast rebuttal to Mr. Toomey of the summer.

"There's no doubt in my mind that these commercials -- and the fact that I think Toomey's run a more disciplined, focused campaign in the last two months -- have put him into this lead," said Mr. Madonna, whose own poll last week showed Mr. Toomey with a nine-point edge.

"And I think it's also partly the problem Democrats have that the recession may be a double-dip, that we're not out of it."

Yet one piece of data from the Rasmussen poll seemed to run counter to that perception: Among the plurality of voters who ranked the economy as the No. 1 concern, Mr. Sestak led 48-40 percent.

Sestak campaign spokeswoman April Mellody expressed confidence that the campaign was in good shape heading into the fall -- when voters start seriously tuning in and when the Sestak campaign can afford to start competing on the airwaves.

"It is clear despite an entire summer of negative advertising from the Toomey campaign and his out-of-state special interest friends that voters in Pennsylvania understand that Joe Sestak is the candidate who can be trusted to fight for them while Pat Toomey will always be on the side of Wall Street," she said.

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