It's the classic Democratic elite "we know better" argument. Anyone who votes for Trump is clearly stupid or has been fooled. The idea that someone could knowingly vote for Trump is just not even something you can comprehend.
I, on the other hand, meet a lot of people who find the other candidates completely unpalatable. Jeb didn't really seem to want it, and most people are sick of the Bushes. Rubio is an empty suit in many ways reminiscent of Obama, and Cruz is just one of the most loathsome people in the US. Trump is rude at times and no, he doesn't express things the way I would, but there is a sense that he is not spouting out positions that others have paid him to have, or that were polled to death by campaign managers. He is a businessman who can legitimately work at getting things done. More than that, he has grasped the fundamental issues that are bothering many Americans: (1) uncontrolled immigration leads to a host of problems, and (2) free trade has not worked to our advantage as much as it could or should. He is for a strong military but doesn't want to go out and get involved needlessly in other peoples' wars. And more importantly, he has generated turnout that Republicans were DYING to see for years.
ἡ δὲ κἀκ τριῶν τρυπημάτων ἐργαζομένη ἐνεκάλει τῇ φύσει, δυσφορουμένη, ὅτι δὴ μὴ καὶ τοὺς τιτθοὺς αὐτῇ εὐρύτερον ἢ νῦν εἰσι τρυπώη, ὅπως καὶ ἄλλην ἐνταῦθα μίξιν ἐπιτεχνᾶσθαι δυνατὴ εἴη. – Procopius
Ummaka qinnassa nīk!
*MySmiley*