That's a mouthful of legalese. In essence, the federal judge ruled that people cannot be compelled to pay into the insurance fund that will cover the costs of Obamacare. The idea behind such a mandate is if you have the widest pool of people participate, both the sick and the healthy, insurance risk is kept down and costs stay affordable. Without such a mandate, it's most likely that only the sick or those fearing illness and needing health care coverage will pay the mandate. Costs would probably become much higher because health insurers would consider those purchasing the mandate risky customers (Read: more likely to file claims) and charge accordingly.
In America we are compelled to pay for automobile insurance because theoretically there's a future risk of liability (someone might get hurt).
By contrast, the plaintiffs in this health care case argue that the new law requires people to obtain health care insurance simply because they exist.
By this logic, you can extrapolate further and assume that the judge's holding will lead to exorbitantly expensive fees for the ailing and those fearing future risk that they will get sick and need health insurance. Therefore, they will not exist.