Stanford Professor Michael McConnell, writing in the Wall Street Journal, argues that the Slaughter Rule end run is unconstitutional:

It may be clever, but it is not constitutional. To become law-hence eligible for amendment via reconciliation-the Senate health-care bill must actually be signed into law. The Constitution speaks directly to how that is done. According to Article I, Section 7, in order for a "Bill" to "become a Law," it "shall have passed the House of Representatives and the Senate" and be "presented to the President of the United States" for signature or veto. Unless a bill actually has "passed" both Houses, it cannot be presented to the president and cannot become a law.

To be sure, each House of Congress has power to "determine the Rules of its Proceedings." Each house can thus determine how much debate to permit, whether to allow amendments from the floor, and even to require supermajority votes for some types of proceeding. But House and Senate rules cannot dispense with the bare-bones requirements of the Constitution. Under Article I, Section 7, passage of one bill cannot be deemed to be enactment of another.

The Slaughter solution attempts to allow the House to pass the Senate bill, plus a bill amending it, with a single vote. The senators would then vote only on the amendatory bill. But this means that no single bill will have passed both houses in the same form. As the Supreme Court wrote in Clinton v. City of New York (1998), a bill containing the "exact text" must be approved by one house; the other house must approve "precisely the same text."

These constitutional rules set forth in Article I are not mere exercises in formalism. They ensure the democratic accountability of our representatives. Under Section 7, no bill can become law unless it is put up for public vote by both houses of Congress, and under Section 5 "the Yeas and Nays of the Members of either House on any question . . . shall be entered on the Journal." These requirements enable the people to evaluate whether their representatives are promoting their interests and the public good. Democratic leaders have not announced whether they will pursue the Slaughter solution. But the very purpose of it is to enable members of the House to vote for something without appearing to do so. The Constitution was drafted to prevent that.