Senate Majority Leader Harry Reid has announced that while Democrats have a number of options to complete health-care legislation, he may use the budget reconciliation process to do so. This would be an unprecedented, dangerous and historic mistake.

Budget reconciliation is an arcane Senate procedure whereby legislation can be passed using a lowered threshold of requisite votes (a simple majority) under fast-track rules that limit debate. This process was intended for incremental changes to the budget—not sweeping social legislation.

Using the budget reconciliation procedure to pass health-care reform would be unprecedented because Congress has never used it to adopt major, substantive policy change. The Senate's health bill is without question such a change: It would fundamentally alter one-fifth of our economy.

The first use of this special procedure was in the fall of 1980, as the Democratic majority in Congress moved to reduce entitlement programs in response to candidate Ronald Reagan's focus on the growing deficit. Throughout the 1980s and '90s, reconciliation was used to reduce deficit projections and to enact budget enforcement mechanisms. In early 2001, with projected surpluses well into the future, it was used to return a portion of that surplus to the public by changing tax rates.

Senators of both parties have assiduously avoided using budget reconciliation as a mechanism to pass expansive social legislation that lacks bipartisan support. In 1993, Democratic leaders—including the dean of Senate procedure and an author of the original Budget Act, Robert C. Byrd— appropriately prevailed on the Clinton administration not to use reconciliation to adopt its health-care agenda. It was used to pass welfare reform in 1996, an entitlement program, but the changes had substantial bipartisan support.