MYRTLE BEACH, S.C. -- Speaking just six miles apart on Friday morning, Donald J. Trump and Senator Ted Cruz of Texas renewed their bitter personal feud, while their supporters echoed the candidates' language and themes - a sign that the bitterness between the two men has now seeped deeply into the feelings of voters. Mr. Trump called Mr. Cruz "the biggest liar I've ever seen," a line he has been pushing all week. Trump supporters, some of whom said they had once considered supporting the Texas senator, largely agreed with Mr. Trump's harsh assessment. "I'm very disappointed in Ted Cruz...