By STEPHEN GROVES WASHINGTON (AP) — After a tumultuous and unproductive session of Congress, nearly 50 House members decided either to not seek reelection or to run for a higher office this year, leaving Democratic vacancies in several tight races that could tilt control of the House to either party. Both Republicans and Democrats have had their fair share of turnover — with former House Speaker Kevin McCarthy, a Republican, the most prominent — but Democrats are also losing prodigious fundraisers who have successfully held off GOP challengers in recent years.