Senator Clinton called the Enzi health bill, which would let small companies band together to buy health insurance across state lines at a good price, “a bait and switch for small businesses,” and claimed it would provide employees with “no guarantee that the benefits available to you initially” would be there later.

In response to a question from The New York Sun, Mrs. Clinton said that a Democratic health plan would provide the economies of scale Senator Enzi’s bill envisages without allowing companies to dodge state laws intended to protect employees.

Mr. Enzi responded to Senator Clinton’s attack on his bill in a written statement. “The fact is, this bill gives consumers more choices, and forces insurance companies to compete,” he said. “Health insurance premiums will go down for American workers.”

When asked whether she supported allowing small businesses joining together to use bloc purchasing power to buy insurance plans, Senator Clinton said, “We have a Democratic alternative that actually permits pooling for small businesses. Senators Durbin and Lincoln have led our efforts to create “a system” similar to the Federal Employer Health Benefits Plan, so we have a plan that by any objective measurement would actually work without depriving people of these benefits.”

Republican control of Congress prevents the Durbin-Lincoln bill from coming to a vote, so the Congressional Budget Office has not analyzed what the Democratic measure would cost.

But Mrs. Clinton was sure it would be better than the Enzi bill. “Embedded in the Enzi approach is the abandonment of state insurance regulations,” she said.

“Bill Nelson was just very strong on saying that this just turns our back on what it means to make sure that when you buy an insurance policy – from whomever you buy it – you actually get what you’ve bought, you get the coverage,” Ms. Clinton said. “And even though this would be very limited coverage – in our view, much too limited, because of what would be eliminated – there’s no guarantee you would even get that.”

“New Hampshire tried to do what the Enzi bills does, and create this association approach for health insurance,” said Mrs. Clinton. “They implemented it, they ran into so many problems, and they had so many people that were dropped from insurance because they were a little too old, or they had a preexisting condition, or they got sick during the year, that based on their experience, they rejected it.”

Mrs. Clinton sought to frame the Enzi bill as a women’s issue, claiming it would jeopardize access to contraceptives. “Women of reproductive age spend about 70% more out of pocket for healthcare costs than men at the same age,” said Ms. Clinton. “In New York State, contraceptive equity is already law, and it should serve as a role model for the rest of the nation. I’ve said it before, and I’ll say it again, if insurance companies are going to cover drugs like Viagra, then they should certainly cover prescription contraceptives.”

America has the highest rate of unintended pregnancies in the developed world, Senator Clinton said, and most “could be prevented if we removed the barriers that stand in the way of women obtaining affordable contraception. The Bush/Enzi bill will only make the obstacles for women’s health higher.”

“I honestly have no idea how one could look at this bill, with even a limited knowledge of how health insurance works in this country, and come to that outrageous conclusion,” Mr. Enzi retorted. “It could not be further from the truth.”

Mr. Enzi challenged Senator Reid’s and Mrs. Clinton’s claims about his bill’s impact on the availability of contraceptives, arguing that it was protected under a 2000 Equal Employment Opportunity Commission ruling barring employers from denying benefits for prescription contraceptives under their health plans, and a related federal court decision in 2001.