text:  mounting one of the most significant challenges in that primary to Trump. Tonight he opened by saying, thank God for Donald Trump. And in much the same way, Nikki Haley was the most significant primary challenger this year. She had called Trump unhinged. She had said just as recently as February that many of the same politicians who publicly embraced Trump privately dread him. Tonight she fully embraced him, made it perfectly clear, she said, that he has her strong endorsement.