I happen to agree with much of what Tancredo says about illegal immigratrion. However, to most liberals and some GOP'ers, and even some around here, his ideas are 'harmful'. ome here think they are 'harmful' to the GOP.
The unfortunate thing is that we can't determine whether an idea is harmful, typically, without first passing it through the test of time. Then, from the vantage point of looking at it as history, we can make a determination. Otherwise, it's all just philosophical and theoretical debate. Which is all the communist manifesto was back when Uncle Karl was beating his chest atop trash cans.
I have an idea that all books should be pass my inspection and I should have the final say as to whether or not they are suitable for the populace, and for this *service* I should be paid handsomely.
That idea may be harmful, but unless it's implemented then we really won't know.
But in sincerity, I'm not and haven't advocated book burnings, but I think books can be harmful.