Not viable, eh? In what sense? It would appear that DT has a very good chance of being the nominee.
Winning the nomination is not winning the election.
Show me the numbers demonstrating that Trump will do especially well in November.
You shouldn't have any trouble finding them, just look up Donald's loudly Trumpeted polls, and then run your finger across to the general election. He's a weak candidate, the least likely to win among the top 4 vying for the nomination. So he is certainly less viable by his own favored measurement --the polls.