The Supreme Court is struggling with whether to put a new roadblock in the way of terrorism victims who are trying to obtain nearly $2 billion in judgments against Iran.

The justices heard arguments Wednesday between the central bank of Iran and relatives of terrorism victims, including many who were among the 241 Marines killed in Lebanon in 1983.

The issue is whether Congress butted into the business of federal courts when it passed a 2012 law allowing the families to be paid from assets of the central bank that are held in the United States.

Several justices raised questions about whether Congress impermissibly tried to dictate the outcome of the dispute. Chief Justice John Roberts said it is "our job to decide cases."