There should be context to all decisions making. If the person has extreme views and, most importantly, they are very vocal about it to the point you don't think they'll fit into the culture of your organization, then I see no problem with not hiring them on that basis.
But at the same time if the person is able to treat others respectfully, not force their views on others, and keep personal life and business separated, then I don't see the problem with hiring them regardless of their views.
I'd be more concerned hiring a moderate democrat/republican/green/etc who forced their views on other people on the job, than hiring someone holding (what mainstream society considers) extreme views[^] and rarely talks about it at work.
[^] Note: calling for violence and coercive behavior is another story.
Trump is obnoxious but Stalinist purges are not an answer for it.
millions of illegal immigrants, as a candidate to immigration myself, following the rules, I see no problem with that.
I'm not equating Trump and Hitler, btw. But Hitler proves that being mainstream means nothing.
Separately, it is also my perception that both men's source of power are somewhat similar. They both have supporters that want an aggressive, authoritarian leader to change things drastically because the current direction isn't working for them. I think that's a dangerous thing to wish for.
It means that you better take the position serious and engage in a real discussion. By labeling one side good and the other evil you just drive both sides more into towards the extremes.
Not the same thing at all.
On one hand, supporting someone who's genocidal or something is bad.
Trump, on the other hand, might be the exact terrible thing this country needs to reign in government. Lets say he wanted to detonate a nuclear bomb off the coast of North Korea. (Borrowing from the most recent Dan Carlin/Common Sense podcast [0])
This would be objectively bad. We should not be nuking anything, anywhere, ever. Period.
If trump-the-president wants to do this, you might really quickly find people talking about the constitutional limits to declare war that Congress is supposed to maintain.
So, they might step in and say "Actually, presidents cannot unilaterally declare war. Oh, and they cannot create internment camps, or do deep packet inspection on the entire internet, or collectivize businesses, etc."
In other words, when a terrible guy gets into office, everyone else might wake up and try to roll back his power. So, it might be a net win, though it's a hell of a gamble to get there.
So, by that line of reasoning, I could see the GOOD that a trump presidency could bring about.
Even if I couldn't, I still don't know what the limit is for donating money to a cause and forcing separation with a company. The free-speech guy in me says it's fine, but... I really don't like trump.
[0] http://www.dancarlin.com/common-sense-home-landing-page/
Now, I don't particularly believe those things. But it is possible to hold those views and support him, despite not agreeing with his more racist, misogynistic ones.
Censoring people by expulsion in this way is a very dangerous path to start down. Especially when you don't even really know what Thiel's views are. Support of a candidate is an extremely broad brush.
Despite the objectively horrible viewpoints advanced by the Trump campaign, they do not approach David Duke's viewpoints.
From some points of view, pro-abortion advocacy is an unconscionable violation of human rights and outweighs religious (Muslim profiling) and racial (seizing remittances from Mexican nationals) concerns; it is a rationally-approached choice of a lesser of two evils.
This isn't strict cultural relativism; the argument has merit. I assert that including alternate viewpoints (but prohibiting bigoted / wrongful actions) strengthens institutions. The best demonstration of the strength of a world view is to accept discussion of alternate viewpoints. If we're right, we shouldn't be afraid of the alternative.
And Peter Thiel might be one of them.
If your goals are a mix of both, weigh and decide.
On the issue of Peter Thiel, for those of you that believe it's wrong to fire someone based on their political actions, is there any limit? If David Duke ran for office, or the Ku Klux Klan fielded a candidate for president, and someone gave a high profile speech endorsing them and supported their campaign with a million dollars, would it still be wrong to part ways with that person?