LANCASTER -- For the two trailing Democrats in the 2006 Pennsylvania Senate race, yesterday's debate was their final chance to make the case -- face to face -- that the Democratic establishment made a mistake when it put its money and power behind conservative Democrat Robert P. Casey Jr..

In an hour and 45 minute debate at Franklin & Marshall College over who should challenge Republican Sen. Rick Santorum in November, Mr. Casey, the state treasurer, piled most of his criticism on Mr. Santorum, who he described as content to "stay the course" as Pennsylvania families struggle with health care costs and gasoline prices.

But the other two candidates -- Philadelphia lawyer Alan Sandals and Bucks County history professor Chuck Pennacchio -- accused Mr. Casey of taking cowardly positions on issues ranging from Iraq to accepting money from lobbyists.

Mr. Pennacchio, who raised just $25,500 in the first quarter, went after Mr. Casey for taking contributions from business and political action committees and described himself as "the only clean candidate."

Mr. Sandals criticized Mr. Casey for being "too timid" in his agenda.

"We are not going to win [in November] if we simply have a candidate ...who offers more of the same," Mr. Sandals said.

But Mr. Casey, who has raised $8 million and has $4.5 million on hand to Mr. Santorum's $9 million, argued that his ability to buck even his own party makes him well suited for the Senate.

"Anyone who knows me -- knows that I am very, very independent," Mr. Casey said. "No one controls the way that I vote and it should it be that way in the United States Senate."

But the debate did elicit significant differences among the three candidates on some of the most contentious issues and most strikingly on the U.S. military presence in Iraq.

Mr. Casey has rejected the proposal by U.S. Rep. John Murtha, D-Johnstown, to withdraw troops from Iraq over a six-month period while keeping a special strike force in the region to re-enter as needed. And he also opposes creating a timetable for withdrawal.

By contrast, both Mr. Pennacchio and Mr. Sandals praised Mr. Murtha's call for withdrawing troops.

"We support our troops by bringing them home and redeploying them in areas that actually are hotspots," Mr. Pennacchio said.

On domestic issues, the moderator steered away from abortion -- the most discussed difference among the Democratic primary candidates. Mr. Casey favors overturning the landmark decision Roe vs. Wade, while Mr. Pennacchio and Mr. Sandals support abortion rights.

But Mr. Sandals and Mr. Pennacchio blasted Mr. Casey's support for now-Supreme Court Justice Samuel Alito, who was criticized by liberal groups as a danger to privacy rights.

Mr. Sandals said Mr. Casey had abandoned women and labor by announcing he would have voted to confirm Justice Alito.

"Where do you stand -- be brave Bob," Mr. Sandals said.

Mr. Pennacchio said it was "a sham" to watch Senate Democrats "giving a free pass" to Justice Alito, and added that as a senator he would have defied Democratic Party leaders by filibustering both Chief Justice John Roberts and Justice Alito.

The three candidates also revealed differing views on President Bush's tax cuts.

Mr. Sandals said he favors returning tax rates to what they were under the Clinton administration, and said he would use money gathered from increasing the rates on capital gains and dividends to fund new private accounts that would supplement current Social Security benefits.

Mr. Pennacchio said he would rescind the president's tax cuts and raise the marginal tax rate on the top two percent of taxpayers.

Mr. Casey, by contrast, would only roll back the president's tax cuts for the top 1 percent of Americans.

The candidates were also asked to list the first three pieces of legislation they would introduce if elected.

Mr. Sandals said he would author legislation aimed at slowing global warming on his first day. He also said he would push for a stronger law to protect the pensions of older Americans, and that he would exempt Americans older than 63 from paying taxes on income up to $30,000.

Mr. Pennacchio said he would introduce a bill creating a universal single-payer health care system, which Mr. Sandals also favors but Mr. Casey opposes. Mr. Pennacchio also said he would advocate for legislation creating "a living wage" and improving fair trade.

Mr. Casey said his first three proposals would give every 4-year-old access to pre-kindergarten education, set up a panel to dig into budget abuses and enact tougher restrictions on lobbyists.