The Supreme Court is hearing arguments today challenging the Affordable Care Act, also known as Obamacare, according to NBC News. The high court will hear from 18 Republican states, led by Texas, who are appealing to the justices to get rid of Obamacare.

They argue that Obamacare’s requirement that almost all Americans must have health insurance or be forced to pay income tax penalties, in the form of individual mandates, is unconstitutional. The Affordable Care Act affects more than 10 million people nationwide and offers protections for those who have pre-existing health conditions.

Even if the Supreme Court sides with Republicans and decides the individual mandate is unconstitutional, the court will still have to rule whether to strike down all of the Affordable Care Act or retain the rest of it. The court now has a 6-3 conservative majority. Despite this, Chief Justice John Roberts and Justice Brett Kavanaugh so far do not appear to be willing to abolish all of the ACA, according to the Associated Press.

“Would Congress want the rest of the law to survive if the unconstitutional provision were severed?” Justice Roberts said. “Here, Congress left the rest of the law intact. That seems to be a compelling answer to the question.”

The Supreme Court upheld Obamacare during a challenge eight years ago. However, the GOP-led Congress reduced the tax penalty down to zero three years ago. The Supreme Court is expected to make its decision by next spring.