An effort to repeal the antitrust exemption for health insurers took a step back this weekend, when Democratic leaders left it out of a package ^[1]of changes to the health system overhaul bill the Senate is voting on this week.

Sen. Patrick Leahy (D-Vt.) three weeks ago offered language to repeal the exemption as an amendment to the Senate’s health care legislation. The proposed repeal would subject health and medical malpractice insurers to federal laws that forbid firms from fixing prices, rigging bids, or dividing up markets with competitors.

In a statement on Saturday, Leahy said he was “disappointed” the amendment would not be a part of the Senate’s debate.

Similar language, which represents a partial repeal of the 1945 McCarran-Ferguson Act, is included in the House version of the legislation. Leahy said he will continue to push for the repeal as the the Senate and the House work to reconcile their bills.

The amendment, which had the support of Majority Leader Harry Reid (D-Nev.), was a casualty of Reid’s well-chronicled struggle for the 60th vote in favor of the bill from Sen. Ben Nelson (D-Neb.)

Nelson, a former insurance executive, had earlier expressed reservations about the repeal. Insurers had also lobbied ^[2]to keep the provision out. Nelson also has been at the heart of tense negotiations over other provisions of the bill, including whether it would include a government-run health care plan option and restrictions on taxpayer funding of abortions.

Liberals have called ^[3]attention to the repeal’s notable absence in the latest Senate package, and backers of the repeal have urged ^[4]House Democrats to fight to keep the repeal in the final bill.

But congressional Democrats have little room to deviate from the Senate version of the legislation. “It is very clear that the bill — the final bill — to pass in the United States Senate is going to have to be very close to the bill that has been negotiated here,” said Sen. Kent Conrad (D-N.D.) on “Fox News Sunday.” “Otherwise, you will not get 60 votes in the United States Senate.”

Whether the House repeal language will survive in a House-Senate conference negotiation over the final version of the bill is largely dependent on what Nelson is willing to give up. In an interview with CNN, Nelson laid out several provisions in the House bill that are deal-breakers for him, but he did not single out the antitrust exemption as one such deal-breaker.