By Lewis Krauskopf NEW YORK (Reuters) – A U.S. presidential race that is about to heat up could add a fresh wrinkle to markets in 2024, as investors gauge the potential for post-election changes in fiscal spending, taxation and other policy areas. For months, the Federal Reserve’s monetary policy trajectory and the U.S. economy have consumed investors, with expectations for 2024 rate cuts by the central bank fueling an explosive stocks rally in late 2023 and putting the S&P 500 within striking distance of a fresh record high. The importance of those factors for asset prices is unlikely to wane…