Sens. Patrick Leahy (D-Vt.), Jim DeMint (R-S.C.) and Barbara Mikulski have all won reelection. Neither of the trio had been expected to lose, though Mikulski’s race was close. Leahy will now serve a seventh term in the Senate, while DeMint will serve a second term. Mikulski, meanwhile, becomes the longest-serving female member of the United States Senate…