I do not believe Trump is significantly more intolerant than HRC or any other likely presidential candidate, he simply focuses his rhetoric on populist ire across all of his positions. It's the only trick he knows so he does it again and again.
Additionally, HRC has in the past advocated a nearly identical "wall" policy but used softer rhetoric:
https://www.youtube.com/watch?v=3gUAdAYFbIc
GOP candidates for several elections have said much the same stuff Trump is saying only with a rhetorical style more like HRC's. Trump borrows economic populism (and its racist undertones) from the rust belt rhetoric of democrats.
> If you don't believe Trump's intolerance poses a real threat
This is not my belief. I believe both Trump's and HRC's intolerance both pose a major threat. I also believe that the trend toward unabashed executive power is the biggest threat to stability. HRC and Trump both show a similar chance of abusing this, and fortunately congress would be more vigilant about preventing Trump from abusing it, since he has not spent years aligning interest groups in preparation for his day in power.
I could not vote for either of the two major party candidates, my position is not to defend Trump but to apply some of the same criticisms to HRC which seemingly exist in the blind spot of Altman, Graham, and other HRC supporters.