A certain commie and I were were friends for a time in graduate school, but friendship is fragile among those for whom ideas matter. Unlike the ordinary non-intellectual person, the intellectual lives for and sometimes from ideas. They are his oxygen and sometimes his bread and butter. He takes them very seriously indeed and with them differences in ideas. So the tendency is for one intellectual to view an ideologically divergent intellectual as not merely holding incorrect views but as being morally defective in so doing.
Why? Because ideas matter to the intellectual. They matter in the way doctrines and dogmas mattered to old-time religionists. If one's eternal happiness is at stake, it matters infinitely whether one 'gets it right' doctrinally. If there is no salvation outside the church, you'd better belong to the right church. It matters so much that one may feel entirely justified in forcing the heterodox to recant 'for their own good.'
The typical intellectual nowadays is a secularist who believes in nothing that transcends the human horizon. But he takes into his secularism that old-time fervor, that old-time zeal to suppress dissent and punish apostates. It is called political correctness.
And as you have heard me say more than once: P.C. comes from the C. P.
The above is excerpted from a longer entry, A Red-Diaper Baby I Once Knew: Anecdotes Illustrating Leftist Illusions.