A challenge to the Senate health bill's constitutionality failed on Wednesday afternoon in a party-line vote.

Sens. John Ensign (R-Nev.) and Orrin Hatch's (R-Utah) point of order arguing that the Senate bill is unconstitutional under the Interstate Commerce Clause and Fifth Amendment of the U.S. Constitution failed in a 39-60 vote.

The vote was the first in a series Wednesday afternoon as senators prepared to invoke cloture for final passage of the Senate's health bill.

Conservatives have alleged for some time that elements of the health bill, most particularly the mandate that individuals buy some sort of health coverage, violate the Constitution.

Sen. Jim Bunning (R-Ky.) is the lone senator to miss the vote.

This post was updated at 4:10 p.m.