2: Because it's easy to imagine. Deep down we all know that all the other candidates represent the continued perpetuation of a static oligarchy that wants to slowly decay the rights and power of anyone not them but otherwise maintain the status quo. Which hasn't had something like a nuclear war in a really long time. Even though Trump is also probably that, it's easy to imagine because of all the hate and populism that he rides on that he'd represent real, and really destructive, change from that status quo.
It's easy to imagine all kinds of things about the Trumpster, and that's precisely the point of the populist strategy: be as politically vacuous as possible and let the people project their deepest hopes and fears upon you – the field will automatically divide itself into idolizing supporters and demonizing opponents, thanks to group dynamics. If you have to promise something, make absurd promises or no promises at all – you'll never get taken to task for not doing the impossible, and your voters won't care about things you
could have done but never cared to mention in your campaign speeches. The boring truth is that we simply don't know for sure that Trump will actually do
anything at all as president. For all we know, he might disrupt the political system or start a world war, or just sit in the oval office jacking it to Celebrity Apprentice reruns. It's not like
he has planned that far, we can be sure of that.
Having said that, we
do know a few things about the remaining two presidential candidates (Bernie was out of the game from day one):
– Trump will not bring back American jobs (and neither will Hillary).
– Trump will not fix campaign financing (and neither will Hillary).
– Trump will not restrain Wall Street fuckery (and neither will Hillary).
– Trump will not end U. S. proxy wars in the Middle East (and neither will Hillary).
– Trump will not withdraw support from the genocidal Israeli government (and neither will Hillary).
– Trump will not take global warming seriously (and neither will– no wait, she might actually
at least pretend to take it seriously; that's a plus).
In other words, Trump is only marginally worse than the front-runner of the presidential race, and painting him as the Antichrist is just a bit of fun.