We see exactly this kind of thing today. Think about certain political statements to the effect that "immigrants are horrible people and we should keep them out. if we had more immigration it would be horrible". <today they mean it's bad, not in the past>. "But when my forefathers came here, it was different, we were good people <white you mean?>, our forefathers did all this great stuff. immigrants today are not like that". So it's clear this willful lying to yourself is still going on.