WASHINGTON, June 27 — It’s not every day that one Supreme Court justice, even one as rhetorically unrestrained as Justice Antonin Scalia, characterizes another justice, let alone the chief justice of the United States, as a wimp and a hypocrite.

Yet Justice Scalia did something very close to that, not once but twice, in separate opinions on Monday. As a result, he has served to lift the curtain a bit on the differences within the powerful five-justice conservative bloc that has marched in lock step through much of the term, bent on reshaping the law and, in several important areas, well on the way toward doing so.

In the campaign finance case, he accused Chief Justice John G. Roberts Jr. of “faux judicial modesty” for writing an opinion that in Justice Scalia’s view effectively overturned the court’s 2003 campaign finance decision “without saying so.” The clear implication was that the chief justice lacked the courage or honesty to overturn the precedent openly as Justice Scalia himself would have done.

“This faux judicial restraint is judicial obfuscation,” he said.

And Justice Scalia was scathing in his criticism of an opinion signed by Chief Justice Roberts that limited, but did not completely abolish, the right of taxpayers to go to court to challenge government expenditures that promote religion. Justice Scalia would have gone on to shut the courthouse door completely, not simply limiting but overturning the precedent that the new ruling invoked.