Senate races next week could hold the key to whether the stock market glides through the year-end in a typical post-midterm election rally or gets hit with a fresh bout of volatility. “If we have a really uncertain situation, where the Senate is divided and candidates are threatening recounts, that’s really not good,” said Robbert van Batenburg, director of market strategy at Newedge USA LLC in New York. Such an outcome, while considered unlikely, nevertheless rekindles uncomfortable memories for some of the 2000 presidential election, when George W.