Far from uniting the Republican Party as he claims he has, Donald Trump has been unable to win over a substantial bloc of voters he may need if he is to take back the White House in a repeat election match-up against President Joe Biden. After winning South Carolina’s Republican primary vote on Saturday, Trump is firmly on track to secure the party’s nomination in the coming weeks. But rival Nikki Haley’s better-than-expected showing in South Carolina exposed weaknesses on Trump’s flank, particularly among more traditional Republicans and moderate voters.