Sen. Barbara A. Mikulski (D-Md.) and her GOP challenger, state Sen. E. J. Pipkin (Queen Anne's), sparred over taxes, military spending and health care costs last night in a televised debate that reflected the increasingly acrimonious tone of the campaign.

Mikulski, 68, seeking a fourth Senate term, accused Pipkin of making "radical, right-wing accusations" about her opposition to Bush administration nominees for the federal bench, and of running a "cookie-cutter campaign" of misrepresentations "right out of the national Republican playbook."

She also criticized his career on Wall Street, where he sold high-yield so-called "junk bonds," describing him as part of a "culture of corporate raiders."

"The choice could not be clearer," she said during the hour-long debate, sponsored by the Maryland League of Women Voters and aired by Maryland Public Television from its studios in Owings Mills. "My opponent is a first-term-only member of the Maryland General Assembly."

Pipkin, who alleges that Mikulski has voted to raise taxes more than 350 times, pointed to a series of votes that demonstrated, he said, that she has lost touch with her constituents.

He defended his 16 years on Wall Street, saying he had "worked hard . . . honorably and honestly in the investment business," and that junk bonds had been used to finance public works and amenities such as a museum in Baltimore to honor African Americans.

"I believe it is time for a change," Pipkin said. "Going through this campaign process is a very healthy thing. After all, U.S. senators aren't royalty."

Pipkin, 47, has been waging a highly visible campaign in recent weeks, financed largely with his own money. In a series of television ads, he has portrayed Mikulski as a free-spending liberal who scrimped when it came to approving funds for troops in Iraq. "Who knew?" the ads ask.

Mikulski, who holds a considerable edge in fundraising, had spent the early part of the fall campaign emphasizing her ethnic roots in East Baltimore, but has begun to answer Pipkin's spots with her own, depicting him as a remorseless Wall Street trader with no empathy for low or middle-income people.

The debate's sour tone mirrored the messages in the ads.

Pipkin criticized Mikulski's opposition to the Bush administration's prescription drug bill, pointing out that it had broad support from groups such as the American Association of Retired Persons.

"You better believe I voted against that Bush prescription drug plan," Mikulski said. "It helped insurance companies, and gave great subsidies to the drug companies. I wanted to have a prescription drug benefit that would help seniors," she said.

Pipkin said he was concerned about Mikulski's opposition to some nominees for the federal bench.

"The implication is that these judges are too religious or that they are pro-life and they don't deserve a place on the federal bench," he said. Mikulski said she has voted to approve 95 percent of the president's judicial nominees, and that those she opposed were clearly unqualified.

The two will meet again for their second and final debate at 10 a.m. Friday on WTOP radio, 1500 AM.