Washington (CNN) - Congressional Republicans plan to mount a last-ditch challenge Wednesday to the health care bill now moving through the Senate, arguing that a key provision is unconstitutional.
Sen. John Ensign, R-Nevada, has claimed the bill's requirement that all Americans purchase coverage is not authorized "by any of the limited enumerated powers granted to the federal government." He also has argued the mandate violates the Fifth Amendment, which states that private property shall not "be taken for public use, without just compensation."
Congress lacks "the legal or moral authority to force this mandate on its citizens," Ensign recently said. "Is it really constitutional for this body to tell all Americans that they must buy health insurance coverage?"
Democrats are expected to defeat Ensign's point of order and pass a motion Wednesday setting the stage for final passage of the sweeping $871 billion measure. A final vote on the bill is currently set for Thursday morning.
Any measure passed by the Senate would still have to be merged with the $1 trillion version approved by the House of Representatives in November.
Democrats hope to have a bill ready for President Barack Obama's signature before the president's State of the Union address early next year.
"Health care reform is not a matter of if," White House Press Secretary Robert Gibbs said Tuesday. "Health care reform now is a matter of when."