Liberals like to think that Trump's behavior wrt Iran, Russia, and North Korea is a dealbreaker for even conservative military service members. My understanding of Trumpism suggests this should impinge only on Independent types who don't mostly vote R. What are you hearing in general on these subjects?

The SJW association with the Democrats makes them absolutely unappealing to a lot of Trump supporters. They want to to hate who they hate without being told to feel guilty about it, political correctness be damned. Same with the people that see the Republicans as the bastion of conservatism, they'll never vote for another party so long as the Republicans are anti gay marriage, anti abortion, anti immigrant and will vote on the party line every time.
What I had in mind is, people who might watch a couple hours of cable news per week or listen to half an hour of talk radio every day, otherwise no engagement, who literally do not know what's going on in the world. Such a type would still bear liability for their political choices, but it at least salvages honor compared to the cult members with eyes wide open.

You know the latter...

Spoiler Alert, click show to read: 
I don't care what Trump up as long as he keeps triggering liberals.
Trump makes me feel good as a Real American.
Maybe his policies will hurt me, but I know I have to make sacrifices for the greater good as long as the government isn't for the bad people.


etc.

If she wasn't politically toxic with half the country she would have worked (I know she won the popular vote but we don't use that system). Take her policies and have almost any other democrat run with them and they'd probably win. Seeing as she's essentially been running for President since she was first lady she has been far too long in the public eye and is seen as a power hungry expletive. I certainly didn't like her but I'd have preferred her over Trump, I demand at least competence even if I disagree with the policies or individuals.

I wouldn't actually call her strong on defense, she, her husband and Obama were all about the air/drone strike diplomacy. Fine to do a few strikes to make it look like something has happened but never send in ground troops because that's too bloody and messy. She voted for the Iraq war and support the intervention in Libya, that doesn't equal strong on defense, just short sighted.

I think someone like General Clark would do well in a general election for the Democrats over the Republicans in today's environment but he'd have trouble even getting nominated because he's a white male with a military background which means he's not ground breaking enough to excite young democratic voters.
Funny you should mention that, because progressives have (at least since last year) been crapping endlessly on the DNC/DCCC for prattling about "identity politics" yet consistently intervening in local primaries to support white (often male) military veterans (or business persons) over women and minorities with more populist platforms.

So Bush wasn't strong on defense? Who is an example? I'll let Seamus speak for himself, but if "strong on defense" means insert ground troops at the drop of a hat (of course I'm framing it that way because it sounds bad to me), didn't Obama do that in numerous countries throughout Africa and Asia, with special forces and training missions? If it's budgetary, lavish defense spending is bipartisan. If it's about being willing to start a major ground war, I don't recall any candidate in either party explicitly calling for the real deal, like explicitly a ground invasion of Syria/Iran or direct strikes against Russian armed forces... You'll have to explain yourselves.

As for Hillary, without revisiting particulars of her career or person I recall polls showing that her favorability was fairly high among the general population between 2010 and 2015; it's more that she was susceptible to the election propaganda machine, partly because it had a generation to really get in motion, and wasn't effective at counteracting its impact.

I don't know what Clark's positions or orientations are. If he's a Kerry or even a Biden type he's no good for the coming cycle. Kerry or Biden don't beat Trumpism.