I have always seen this as a Trump vs Sanders race. I know it's only the preliminaries, but these are going to be your two big "personalities" that win out with both sides. As I see it as a Trump v Sanders race, I then have to look at the two of them and what they either mean for my nation or myself, or what they will end up doing to these things. This presents me with a very difficult problem...
Sanders sounds awesome on paper, do not get me wrong. All this free stuff, and all this free stuff is basically for me, Mr. Working Poor! Free/cheap school? Less harsh student loans? Living wages? etc? All of it sounds like a socialist dream, but I live in an primarily capitalistic mindset nation. I see job losses as people like my own boss end up cutting me outright when they can't pay for my high wage. $15 an hour would mean I do not have a job or that the cost to stay in this hotel would be almost $100 a night (and you would see this harsh increase on prices literally everywhere if that was the solution by businesses), which it can not currently do. Not to mention the people who already make less than, or the same as, that in management positions, are they going to get paid the same amount as the guy that they hire tomorrow or will there be an increase on them as well? A lot of the increased taxes also wouldn't go where Sanders says he wants to put them, simply because those people he wants to tax would take their money and leave. We're talking 90% of the nations money not in the nation anymore. What does that lead to, folks? I'm pretty sure it's economic collapse. I'm not a genius, but I'm pretty sure Sanders is just promising things he either knows he can not do or is actively trying to plummet our economy (what's left of it). This is ignoring the overall value of the USD will also drop. His solutions to ISIS and "terrorism," in general, are also very weak handed.
Trump, on the other hand, fits my nation's ideas and behaviors frighteningly well, and will be unable to start any concentration camps (and if he does, I'm not a Muslim). He'll be a very strong and loud leader/figurehead, which our nation has lacked for many years. We might be "laughed at" for having someone who's so crass as our president, but those people would also start to fear us again. I do not agree with, like, anything he says, but I do not fear what he desires the way I fear what Sanders desires. Trump can't actually accomplish what he wants, and if he does, it doesn't lose me my job, my apartment, or my way of life, and that's all I really care about. I don't care how the rest of the world sees the US. I do not care about any war (unless it's on our shores). I care about my paycheck, because I work for a living, and have to support 3 people on it. I want that made easier, and stay that way, or I want it left alone so I can do what I need to do in order to increase my ability to support who I gotta support.
I'm not pro-Trump, I'm anti-Sanders.
Edit: If Hillary becomes the democrat against Trump then it literally doesn't matter. They are the same person, one just happens to be female and not hate Muslims.