Tom Tancredo promised to publicly smoke pot if Colorado’s legalization initiative passed. But now, after the initiative did indeed pass, he’s backing out, supposedly because his wife and grandkids were so outraged. 
All of which brings up the question: why do Tancredo’s wife and grandkids care if he smokes pot?
More to the point: why is strident opposition to marijuana a conservative value? Most conservatives wouldn’t care if Tancredo drank a beer in public—what’s so different about pot? Aristotle argued—and lots of conservatives agree—that the key to life is moderation. Tom Tancredo is 67 and has never smoked pot before—surely one joint every 67 years is the height of moderation. At this rate, he won’t have another hit until the year 2080! So where does this total and irrevocable opposition to a harmless pastime come from?
Which brings up a second point: even if conservatives have to hate pot, why hate it so much more than other bad things?
Isn’t promise-breaking morally worse than taking a puff of marijuana? After all, if people habitually renege on their promises, society would crumble. But on the other hand, society can tolerate a relatively high degree of pot smoking. And then there’s the issue of a public figure signaling to the public that he doesn’t take his own commitments seriously. Can anyone imagine Edmund Burke or James Madison publicly promising something—even something as relatively unimportant as this—and then backing out when their wives complained?
Maybe this just goes to show that the Tancredos have a weird relationship. (As one Politico commenter crudely summed up: “Some times the snatch is better than the stash.”) But I think that the Tancredo family’s intransigence is evidence of a systemic conservative opposition to pot. (Seen in, for example, Sean Hannity’s “Christian conservative” claim* that drug legalization promotes “the moral destruction of a human soul.”) And that conservative opposition just doesn’t seem to have any substantive justification, beyond a knee-jerk support for the status quo, or some vague belief that only liberal hippies smoke pot.
* I’ve never been impressed by Sean Hannity’s intellect. But the linked video is especially cringeworthy, as Hannity repeatedly insinuates that supporting legalization means that you also support government-provided drugs andgm medical care. How he discovered that link is anyone’s guess—though his interviewee, Gary Johnson, never really disavows it.