This is an insightful discussion on the meme of tolerance which certainly has informed western thinking and education for a long time. Our present problem is that this meme is not shared by every prospective immigrant group and accepted once they arrive.
It must become an actual condition for immigration and any one teaching intolerance needs to be subjected to summary censure and if necessary, actual silencing. We do exactly that for hate speech and incitement to criminal behavior. This really not subject to fuzzy thinking except by sophists.