Joe Kennedy III Exploring Congressional Bid For Barney Frank's Seat In this photo taken Jan. 7, 2010, former Massachusetts Rep. Joseph P. Kennedy II, left, hugs his son, Joseph P. Kennedy III after introducing him during a campaign event for the senate candidacy of Martha Coakley in Medford, Mass. WASHINGTON - Joseph Kennedy III is taking the first steps toward a run for retiring Rep. Barney Frank's seat in Massachusetts. The 31-year-old Kennedy said Thursday he is forming an exploratory committee and is resigning his prosecutor's job in Middlesex County outside Boston. He is the son of former Rep. Joseph P. Kennedy II and a grandson of the late Robert F. Kennedy. The Kennedy family has seen its influence in Washington fade in recent years as its younger generations have largely shunned public office. The death of Sen. Edward Kennedy of Massachusetts in 2009 left a void for the family. The retirement of Rep. Patrick Kennedy of Rhode Island last year marked the first time in 63 years that there was not a Kennedy serving in elected office in Washington.