I think you guys base far too much of your assessment of politics on cynical platitudes like "just because it's the majority opinion doesn't make it good". That doesn't make it automatically bad either, and I think spitting that line out at every opportunity stifles any real attempt to asses questions.
No, I base my assessment off personally witnessing three decades (and then some) of assorted American asshattery. And having taken graduate courses on public opinion and finding that it's been scientifically proven that the vast majority of the public--regardless of educational level--have no idea why they hold the opinions they do, will change their opinions at the drop of a hat in response to external stimuli, will rationalize like there's no tomorrow to create a justification for their opinion, and even if confronted with hard evidence that their opinion changed from a previous point in time, may in fact deny the existence of said previous opinion.
In short, public opinion is about as malleable as warm Silly Putty, and most opinions are essentially irrational, even if they don't seem so to the holder. If public opinion
right now is against repealing the 14th Amendment, that's great. One effective campaign of demogoguery and/or one high-profile immigrant criminal may be all it takes to get a 10-15% opinion shift. It's cynical, but it's hardly a platitude.
What democracies do better than anything, provided they make it past the initial shakedown generation, is remain pretty static politically. American democracy in particular is designed to be static. It takes a lot more than a few loud airheads and rent-a-mobs to change the Constitution, especially the parts that most people have been taught since gradeschool are the good parts.
I agree that extreme changes tend not to occur in mature democracies, and that's heartening. But given that most people couldn't even tell you what rights are guaranteed under the Constitution (nor do they agree that all those rights *should* be protected)...I'm not so sanguine about "the people" as a responsible bulwark against extremism.