Here's a primer on why the Democrats' failure to include a severability clause in the legislation opened the entire package up to being stricken by the court. You can read the entire ruling below.
By determining the entire law must be wiped out, Vinson went farther than a different Republican-appointed judge in Virginia who declared the mandate unconstitutional late last year. The Obama administration has appealed the Virginia ruling, and is expected to appeal this one.
Vinson declined to enjoin the law, however, and that means implementation in the 26 states will continue pending higher-court rulings.
The question, as the plaintiffs framed it, is whether Congress can require citizens to purchase a product -- health insurance -- under its powers to regulate interstate commerce. Conservatives -- who originally conceived of and supported the individual insurance mandate -- have argued in numerous lawsuits that the government doesn't have the power, as they put it, to "regulate inactivity."
Before Democrats passed the health care law, legal experts across the spectrum largely held that a Constitutional challenge was futile. But in the intervening months, the question of the mandate has exposed a partisan rift on the federal bench.
In a preliminary ruling back in October, Vinson hinted pretty strongly that he was skeptical of the government's argument. At the time, he called the provision "unprecedented."
"There may be a first time for anything," Vinson wrote at the time. "But, at this stage of the case, the plaintiffs have most definitely stated a plausible claim with respect to this cause of action."
Vinson joins Judge Henry Hudson of Virginia -- a George W. Bush appointee -- in declaring the mandate unconstitutional. Both liberal and conservative legal experts criticized Hudson's ruling for its circular reasoning.