That was thanks to near-complete unity among Democrats in defeating amendments. The party’s senators locked arms to ward off any changes that could endanger the fragile coalition needed to steer their legislation to passage under rules that allow them to avoid a filibuster.

A few more potential threats loomed at sunrise Sunday, particularly on the legislation’s insulin price cap. But Republicans otherwise made little headway during a legislative endurance run of politically tricky votes on immigration, taxes and other issues.

“I want my colleagues to understand what this is really about. These motions … are motions to kill this bill, period,” said Senate Finance Committee Chair Ron Wyden (D-Ore.).