Trump has a vastly higher name recognition than Ted Cruz for example (a gap of 17%). Meanwhile Ted Cruz smokes Trump in net favorability.
Speaking just for myself.. I would have been a strong favorable for Cruz at the time that poll was taken. But now I am at the point where I would register an unfavorable view of him. Over the last few weeks it's been all downhill for him in my esteem.
And the SNL stuff is not good for him at all - give that a chance to hit the polls.