There has been a lawsuit filled against Obamacare in the attempt that it will kill it entirely.
How? Because it didn’t originate in the House. It originated in the Senate. Under the Origination Clause of the Constitution, all bills raising revenue must begin in the House. (<– Follow link for more information.)
Obama calls it a mandate, but when it went for review by the Supreme Court, they ruled that it was a tax.
Want to know more? Visit The Volokh Conspiracy and read: