The Affordable Care Act (ACA), known colloquially as ObamaCare, was upheld by the United States Supreme Court on Thursday, in a 5-4 decision. Chief Justice John Roberts is credited with the deciding vote, in what’s being considered as the most momentous Supreme Court decision in recent years.

According to the ruling, the Supreme Court found that the most controversial part of the ACA, the individual mandate, was valid as a tax, even though it is impermissible under the Commerce Clause, a fact that most opponents believed would kill the law.

“In this case, however, it is reasonable to construe what Congress has done as increasing taxes on those who have a certain amount of income, but choose to go without health insurance,” Roberts wrote in the majority opinion. “Such legislation is within Congress’s power to tax.”

On the dissenting side, Justice Antonin Scalia wrote that viewing the individual mandate of the ACA as a tax is an incredibly dangerous precedent.

“To say that the Individual Mandate merely imposes a tax is not to interpret the statute but to rewrite it,” Scalia said in dissent. “Imposing a tax through judicial legislation inverts the constitutional scheme, and places the power to tax in the branch of government least accountable to the citizenry.”

Locally, leaders applauded the High Court’s ruling. Washington Gov. Christine Gregoire and King County Executive Dow Constantine were happy with the outcome.

“I applaud to today’s Supreme Court decision. Since the Affordable Care Act was signed by the President, we have worked tirelessly to implement it in our state, with my firm belief that it was constitutional and would ultimately withstand legal challenge,” Gregoire said in a statement. “I’m extremely pleased that the majority of the court agreed on the merits of the law highlighted in the brief that I and others submitted on its behalf.”

Constantine said that the decision is another step toward taking care of all citizens of the country and the state.

“I celebrate the Supreme Court’s ruling to uphold the Affordable Care Act. A stable, healthier future has been made possible by this ruling. This is affirmation of our nation-wide bold move toward achieving quality affordable healthcare, and we are moving in the right direction,” Constantine said.