By Sahil Kapur On his home turf at the Republican presidential debate in Miami, Florida Gov. Ron DeSantis sharpened his case against front-runner Donald Trump and tussled with former South Carolina Gov. Nikki Haley as she looked to build on her momentum. Five candidates met on stage Wednesday night, just over two months before voting begins: DeSantis, Haley, Sen. Tim Scott of South Carolina, businessman Vivek Ramaswamy and former New Jersey Gov. Chris Christie. Absent for the third time was T...