Lyndon Johnson, Dick Nixon and Jimmy Carter weren’t very likeable yet they all three were elected president.
How many times did you meet Jimmy? He was a lousy president who surrounded himself with, and took advice from, incompetents, but he was personally likable when I met him four decades ago.
Johnson wouldn't have got to the White House on his own.
Nixon didn't get there the first time and didn't last when he did.
Jimmy Carter only got there once - before people knew who he really was.
I hope Ted Cruz gets reelected, but he will never be president.
Personal unlikeability may not be the main reason, but it doesn't help him any.