Gov. George Deukmejian has endorsed five-term Rep. Robert E. Badham (R-Newport Beach) for reelection. According to Badham aide Bill Schreiber, the endorsement came after Badham agreed to serve as Southern California media chairman for the governor's reelection campaign. Deukmejian's letter, sent Tuesday, cited Badham's seniority "and important role in the House," Schreiber said. Badham is being challenged in the June 3 primary by management consultant Nathan Rosenberg.