After an election night scare, Rep. Louise M. Slaughter of New York won a 15th term Wednesday when her Republican rival conceded the race. The race was close — currently 869 votes — and officials tabulated ballots for almost a week after Election Day. Slaughter's razor-slim margin over Republican Mark Assini shocked Democrats and Republicans — both of whom were surprised by the close race. Assini conceded Wednesday, according to The Rochester Democrat and Chronicle . A Slaughter spokesman confirmed the concession to CQ Roll Call and added Assini called the congresswoman to congratulate her. House Democrats have lost a net of 12 seats so far in last week's elections. The Associated Press has yet to declare a winner in five House races, including Slaughter's contest. Other recent developments in uncalled races include: (more…)