qnli question: When was Carrion Jr. first elected Borough President? sentence: His successor, Democratic New York State Assembly member Rubén Díaz, Jr., who won a special election on April 21, 2009 by a vote of 86.3% (29,420) on the "Bronx Unity" line to 13.3% (4,646) for the Republican district leader Anthony Ribustello on the "People First" line, became Borough President on May 1.