We need somebody to look out for the welfare of the country.  That somebody certainly isn't Trump.  The kindest thing I can say about him is that he is in woefully over his head, and he knows it.  
I am a life-long Democrat, so it's not likely that I would have voted for any of last year's GOP candidates.  I would have been unhappy if any of them had been elected, but at least I wouldn't have been horrified (and afraid).  I could have slept at night if Jeb! had been elected, or Kasich, or Rubio, or even Cruz, confident that they wouldn't blow up the country between midnight and 6:00 am.  Not so with Trump.