US Supreme Court justices signalled on Monday that they saw no procedural barrier to reaching the heart of the dispute over President Barack Obama's healthcare law that requires most Americans to buy insurance or pay a penalty.
During arguments, the justices voiced doubt that a US tax law requiring people to pay first and litigate later should delay the legal challenge to the president's signature domestic legislative achievement.
At the core of the law, signed by Obama in 2010, is a requirement that people obtain health insurance by 2014 or pay a penalty. The question on Monday was whether people can challenge this so-called individual mandate before paying the penalty and seeking a refund.
The law has generated fierce political debate. Underscoring how the issue has divided Americans, hundreds of supporters and opponents marched outside the Supreme Court building.