Crist needs to work with federal and state lawmakers to propose a healthcare amendment to the states for ratification as required by the Constitution's Article V. And if the Article V supermajority of states should choose to ratify the proposed amendment, then Congress will have the constitutional authority that it actually needs to establish a national healthcare program and Crist will be a hero.
In the meanwhile, note that the states already have the 10th Amendment-protected power to individually establish their own healthcare programs. This is evidenced by Massachusetts's RomneyCare. So the states may want to experiment their own healthcare programs for now instead of letting Congress establish a national program.
That statement should disqualify him from as much as running for Dog Catcher in Hollywierd.