Nowhere is former President Donald Trump more vulnerable early this presidential primary season than New Hampshire. The state is hosting its first-in-the-nation Republican primary on Tuesday, and Nikki Haley, the former U.N. ambassador, is the only candidate with a real chance to defeat Trump outright. She now has a clean shot, with Florida Gov. Ron DeSantis ending his campaign Sunday. Trump is vulnerable in New Hampshire largely because of its moderate tradition, though he could get a boost from DeSantis' supporters. Trump is eyeing a victory that would make him virtually impossible to stop. Democrats have a primary, too. President Joe Biden's allies have mounted a write-in campaign designed to demonstrate his political strength.