Tokyo stocks fell Monday morning as tech shares tracked declines in their U.S. counterparts late last week and uncertainty grew over the upcoming U.S. presidential election with incumbent Joe Biden’s withdrawal from the race. The 225-issue Nikkei Stock Average dropped 469.98 points, or 1.17 percent, from Friday to 39,593.81. The broader Topix index was down 29.83 points, or 1.04 percent, at 2,831.00. The U.S. dollar was mostly unchanged in the mid-157 yen range in Tokyo, with Biden’s ending of his bid for reelection having little impact on the currency market, dealers said. At noon, the dollar…