I feel slightly better about this with the knowledge that the office of the president of the US is primarily a status-quo-preserving institution.
The interest groups that care generally want the status quo preserved.
If Trump is not destined to do this, then I think there is little danger he'll be elected.
Note, the same applies to HRC.
Edit: Also, to be clear, if he does have legislative support because enough people support him to elect representatives with similar agendas, that's not really something for me to be worried about, as that would be no different than any other candidate. If it's the will of the people, so be it (as much as I dislike it).