At a U.S. Senate committee hearing Wednesday, key authors of the sweeping 2003 law to overhaul the federal Medicare program accused opponents of trying to sabotage the first portion of the bill that provides a new benefit.

But others senators who voted for the measure are starting to worry that it may not work as well as they had hoped.

At a hearing to look at the new Medicare “drug discount cards” a week after they went into effect, Senate Finance Committee Chairman Charles Grassley of Iowa, said some of the confusion being experienced by seniors is not related to the fact that they have up to 73 different cards to choose from.

“The drug discount card has been the target of a deliberate campaign to discredit it and confuse seniors about how it works. This effort is driven and coordinated by those who opposed the Medicare Modernization Act not because of policy, but because of politics,” Grassley said.

Senate Majority Leader Bill Frist of Tennessee agreed, saying, “What is both surprising and disappointing to me is the fact that some are intent on deliberately confusing the public, and scaring seniors.”

Speaking to reporters after the hearing, however, Senate Minority Leader Tom Daschle disputed charges that Democrats are seeking to undermine the program. “It doesn’t have to be coordinated. Seniors are so frustrated, so angered, and so disappointed by this that it doesn’t take any coordination by Democrats,” he said.

And even senators who supported the law say they are hearing negative reports from those it was intended to help. “Choices are important,” said Democratic Sen. John Breaux of Louisiana, one of the lead members of his party to support the law. “But now I’m concerned we may have too many choices. It’s so incredibly difficult for seniors to make the right decision” about which card might be best.

“The drug card got off to a very rocky start,” said Olympia Snowe of Maine, who added that she is concerned about the precedent the difficulties could be setting for the broader drug benefit set to begin in 2006.

And Democrat Kent Conrad of North Dakota, who said he voted for the bill because he “thought it would be good for my constituents,” said during his trips home in recent weeks “I’ve gotten a lot of blowback” from seniors who are anxious and confused.

Conrad announced he is introducing legislation to make a series of changes in the card program for next year. It will reduce the number of available cards per region to three, as well as bar card sponsors from raising prices or dropping coverage of certain drugs after beneficiaries enroll in their programs.

Medicare Administrator Mark McClellan, however, strongly defended the discount card program. “For seniors who are struggling to pay for their medicines, there are real savings available now,” he said. Medicare officials have estimated that discounts average 15% for brand-name drugs and more than 30% for generics.

For the first time, McClellan also said that Medicare officials are looking closely at the possibility of “auto-enrolling” low-income seniors in a card program if they are already receiving other help with their Medicare bills. Democrats have been urging the administration to sign up those seniors who are eligible for $600 in subsidies this year and next, rather than require those beneficiaries to go through the enrollment process.

Although there are some “practical concerns” to such a move, McClellan said, including coordinating with state governments, “we are definitely interested in pursuing this,” he said.