BATON ROUGE, La. (AP) — Louisiana's two U.S. senators were among the Republicans who agreed to start debating legislation to undo much of Barack Obama's health care law.

The votes Tuesday from Sens. Bill Cassidy and John Kennedy helped Republicans reach the 50 votes — with Vice President Mike Pence as the tiebreaker — needed to move ahead with a weeklong debate and a long list of amendments.

Advocacy groups opposed to the health law rewrite had hoped to persuade Cassidy, a doctor, to help stall the effort.

In a statement, Cassidy described the vote as a "first step." He said: "Nothing changes until the first step is taken."

Kennedy called the current law a failure. In a statement, he described his vote as fulfilling a promise that he would "repeal Obamacare given the chance."