The 2024 presidential election is expected to be decided by slim margins across a handful of battleground states. And one former Republican staffer on Capitol Hill thinks former President Donald Trump needs to reverse course if he hopes to prevent disgruntled GOP voters from defecting to President Joe Biden’s camp. When she suspended her campaign after the Super Tuesday primaries and caucuses, former UN ambassador Nikki Haley notably declined to endorse Trump, saying he would have to “earn” her supporters’ votes in November. And so far, Trump has not made any inroads with his former rival’s ba…