I've written a lot about Donald Trump in this space, basically arguing that his views signify a sea change in the foreign policy discourse in this country. His rise, I've averred, augurs the end of the neoconservatives as a viable political force within the GOP, and the beginning of an "isolationist" (i.e. anti-interventionist) trend in American politics that will upend the Establishment of both parties.

So why didn't I vote for him when I had the chance?

I have to admit I was sorely tempted: the opportunity to make Bill Kristol a very unhappy man was almost too much to pass up. And yet, in the end, when I got my mail ballot, and I sat down and looked at it, I just couldn't bring myself to do it for a very simple reason: the man isn't the movement.

The Trump phenomenon is one thing, and Donald Trump the person is quite another. While the former is to be cheered and encouraged, for reasons I'll get into in a minute, the latter is a very mixed bag.

To begin with, Trump has taken a number of positions I cannot endorse:

He wants to increase domestic surveillance in the name of fighting the "war on terrorism." At once point he suggested we would have to shut down "parts of the internet."

He advocates torture of alleged terrorists and says he would murder their families.

While opposing US intervention in Syria – he once asked Bill O'Reilly "Do you want to own Syria?" – he now says he wants to create a "safe zone" in Syria so the refugees don't have to come here. Call me crazy, but that looks like military intervention to me.

He wants to deport 11 million illegal aliens, an operation that – assuming it isn't stopped by the courts – would be inevitably ugly and provoke massive resistance.

But that's just the beginning of my objections to Trump the candidate. After all, one could conceivably overlook these flaws in the name of changing the general orientation of US foreign policy. And yet, in the case of Trump, even that possibility is foreclosed by his unreliability.

While Trump conceives of his "flexibility" as emblematic of his ability to make a "good deal," the reality is that he flip flops all over the place. One minute he's totally against going into Syria, and the next minute he's constructing "safe zones." His mercurial nature is on display for all to see: once in office, it's entirely possible he could do anything.

I take voting quite seriously, especially when it comes to the presidential level. If I pull the lever for a candidate who subsequently decides he has to bomb Country X, or violate our civil liberties, in the name of some alleged "emergency," then I'm as morally responsible for his actions as if I'd given the order myself.