With Vice President Mike Pence breaking a 50-50 tie, the U.S. Senate voted by a hair Tuesday to start debating Republican legislation to tear down much of the Affordable Care Act.

The vote gives President Donald Trump and GOP leaders a crucial initial victory but launches a weeklong debate promising an uncertain final outcome.

Majority Leader Mitch McConnell of Kentucky said after the vote that the Senate will now begin considering amendments from both parties.

“This is just the beginning, we’re not out here to spike the football,” McConnell said. “This is the long way but we’ll finish at the end of the week, hopefully, with a measure that can either go to the House and be taken up or go to conference.”

In the moments before the vote, most GOP critics of the legislation fell into line to allow debate to begin. They included McConnell’s Kentucky colleague, Sen. Rand Paul.

Last week, McConnell was forced to postpone the vote, lacking the support of conservatives and moderates.

“There will be a lot of different amendments offered by different members trying to craft the bill,” he said. “It’s really entirely impossible to predict in a reconciliation debate exactly what amendments will be offered, or what amendments will succeed. It’s wide open.”

Whatever the Senate approves still requires a vote in the House.

Rick Howlett is host of WFPL's weekly talk show, "In Conversation."