Texas Republican John Cornyn supplemented his Senate salary with a trio of public pensions last year from his days as a Texas judge and elected official—a practice some fiscal watchdog groups have attacked as “double dipping.” Cornyn, who is the minority whip and the No. 2 ranking Republican in the Senate, reported collecting $65,383 in public retirement benefits in 2012 in addition to his $174,000 salary as a U.S. senator. Cornyn’s office did not respond to requests for comment. Elected to the Senate in 2002, Cornyn is a former district judge, Texas Supreme Court justice, and state attorney general. In...