(CNN) The federal judge who declared the Affordable Care Act's individual coverage mandate unconstitutional earlier this month issued an order on Sunday saying despite his previous ruling the law can remain in effect pending appeal.

Texas federal District Judge Reed O'Connor said in his ruling that "many everyday Americans would otherwise face great uncertainty during the pendency of appeal."

Sunday's order also paves the way for a coalition of Democratic states defending the law to appeal O'Connor's original ruling.

O'Connor had ruled that the Affordable Care Act, popularly known as Obamacare, is unconstitutional because Congress eliminated the individual mandate penalty by reducing it to $0. This rendered the mandate itself unconstitutional and the rest of the act therefore cannot stand. However, he did not issue an injunction to stop federal and state governments from enforcing the law.

Still, the decision threw the future of health coverage for millions of Americans on the Obamacare exchanges and in Medicaid expansion into doubt. It also threatened to wipe away popular protections for those with pre-existing conditions, as well as measures that save money for senior citizens on Medicare, let children stay on their parents' policies until age 26 and allow many Americans to access free preventive tests and birth control.

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