Maybe because southern evangelicals hate liars like Ted Cruz after he claiming that Ben Carson dropped out of the race after the Iowa caucuses.
That's why we call him Lyin' Ted.
Clearly this explains why they voted for Trump, who is a paragon of honesty.
Don't forget also the fact that Cruz's dad was involved in the Kennedy assassination. Kennedy won most of the South, so clearly this fact swung the South against Cruz.
You still don't get it. Trump is telling it like it is. No lying. No sugarcoating. No politician's empty talk. Plain and simple truth for everyone to understand.
