HERSHEY, Pennsylvania, May 6 (Reuters) - U.S. Chief Justice John Roberts expressed concern on Wednesday about the public perception of the Supreme Court as an institution driven primarily by political outcomes rather than the law at a time when some prominent voices have raised questions about the top U.S. judicial body’s legitimacy.

Roberts, who has led the court since 2005, appeared to acknowledge dimming public approval of the court, shown in opinion polls over the past few years, as its conservative majority continues to push American law dramatically rightward.

“At a very basic level people think we’re making policy decisions,” Roberts told an audience of judges, attorneys and law students in Hershey, Pennsylvania.

“I think they view us as purely political actors, which I don’t think is an accurate understanding of what we do,” Roberts said.

Roberts, appointed as chief justice by Republican former President George W. Bush, is seen as deeply conservative but also concerned about the court’s institutional credibility and public perception.