Conservatives got an inkling of how bad 2020 would be before the year even started. On Dec. 30, 2019, Gertrude Himmelfarb died. She was just the first of many conservative luminaries to die over the next 12 months — and it is worth remembering each one and what they contributed to conservatism and our country. As conservatism enters its next chapter, without a slew of great ideas or clarity regarding its future direction, learning lessons from these heroes of the past can potentially be a first step in discerning the way forward into the future. Let’s start with Himmelfarb, an eminent historian and also wife of the late Irving Kristol. She wrote scholarly and compelling works about anti-Semitism and the Victorian era that always had contemporary relevance. Even those who disliked her politics could not...