Americans’ opinions of U.S. Supreme Court Chief Justice John Roberts are now much more negative than they were seven years ago, with the most recent reading coming soon after he joined the four Democratic appointees on the court to uphold the U.S. healthcare law. Republicans’ favorable rating of Roberts is down 40 percentage points from 2005, while Democrats’ is up 19. …

Gallup did not measure Americans’ opinions of Roberts between September 2005 and the most recent survey, conducted July 9-12. It is a reasonable assumption, however, that a good deal of the shift in attitudes occurred as a result of the June 28 Supreme Court decision upholding the constitutionality of the Patient Protection and Affordable Care Act of 2010, a ruling whose majority opinion was written by Roberts. …

Mirroring their shift in views of Chief Justice Roberts, Republicans have become much more negative about the Supreme Court since last September. Democrats have become more positive. Twenty-nine percent of Republicans now approve of the court’s job performance, down from 50%, while disapproval has doubled to 64% from 32%. Democrats’ attitudes flipped in the opposite direction, with approval rising to 68% from 46%. Independents’ attitudes have stayed roughly the same, as have the views of all Americans combined.