This isn't the last word on the matter, which is likely headed for the Supreme Court, but it's a very significant ruling. For a lot of reasons.
The percentage of people enrolled who are subsidized
According to the Department of Health and Human Services, about 87 percent of all enrollees in exchange plans are receiving some sort of subsidy. That ranges from 76 percent of Arizonans to 94 percent of the people in Mississippi. But the amount of those subsidies varies widely between and within states, which we'll get to below.
The number of people receiving a subsidy
When you apply that percentage to figures on how many people are enrolled, you get a rough estimate of how many people are on subsidized plans in each state. Florida and Texas, being the largest states to rely on the federal exchange, unsurprisingly have the most people receiving subsidies.
In total, about 4.6 million people on the affected exchanges are receiving a subsidy of some sort.
The average subsidy amount
The average credit received in all of the states is $269 a month. This, too, varies: In Wyoming, it's $422 a month; in Arizona, it's $159 (which is probably why it has the lowest rate of subsidization). In other words, people in Wyoming would have to pay over $5,000 more a year on average if they didn't have the subsidies.
Compared to the penalty for not being covered -- which starts at $95 or 1 percent of income -- the decision won't be a hard one to make.
The number of people paying $50 a month or less
Another way to look at that: In Mississippi, 68 percent of the people being subsidized pay less than $50 a month -- or $600 a year. Take away the state's $415 average subsidy -- which, again, is per month -- and you can see how likely it would be that someone would opt out of coverage.
Of the 4.6 million people who receive a subsidy, about 2.1 million pay $50 or less each month, according to our calculations. If the court's ruling is upheld and those 2 million decide not to renew their policies, Obamacare's enrollment would be gutted.