Among Americans overall, 73 percent have no opinion or are undecided about Roberts, according to the poll, conducted July 11-16. Fourteen percent have a favorable view of him while 12 percent have an unfavorable view.

Among self-identified conservatives, just nine percent have a favorable view of Roberts, who was appointed to the high court by President George W. Bush. Twice as many, 18 percent, have an unfavorable view. Among liberals, 13 percent have a positive view of Roberts while 8 percent have an unfavorable view. Twenty percent of moderates approve of the chief justice.