Backlash is just one of the mechanisms by which constitutions change over time, but it is arguably the most important, because constitution writers and amenders react to past evils; they institutionalize backlash. The German Constitution- especially its protection for human dignity-institutionalizes backlash against Nazism. The Fourth Amendment reflects Revolutionary-era backlash against general warrants and writs of assistance. The Reconstruction Amendments embody backlash against slavery and caste.
Even without formal text, backlash can become embedded in our constitutional understanding. For example, eventual backlash against internment of persons of Japanese ancestry inscribes at least a minimally antiracist principle in our constitutional order. Trump's startling expression of sympathy for the discredited internment policy should be understood as an effort to repeal or revise that antiracist principle. Conversely, Trump's defeat would reinforce the egalitarian understanding of our Constitution. Ironically, the most lasting impact of Trump's candidacy could be to strengthen the vision of our Constitution and nation that he attacks.
Michael C. Dorf, "Donald Trump and Other Agents of Constitutional Change," 83 University of Chicago Law Review Online 72 (2017)