The lawyers, joining various advocacy groups opposed to the nomination, expressed their feelings in a letter to the Senate Judiciary Committee, the Washington Post reported.
The letter said Roberts lacks appreciation for "the important role that an independent judiciary plays in safeguarding individual rights and enforcing legal protections."
The letter was distributed by the Alliance for Justice, which represents the liberal advocacy groups that formally declared its opposition to the nomination this week, the report said.
The professors criticized Roberts' past work in which they said he sought to expand the powers of the president and law enforcement authorities while weakening protections for individual rights. Roberts's confirmation hearing is set to start Tuesday.