Trump's rise to power was absolutely not by chance. However, your analysis isn't satisfactory from a materialist perspective. Rather, it was the sum of neoliberal policies of the last few decades that radically transformed the material conditions of the United States (and other Western capitalist countries), culminating in several economic crises, most notably in 2008. The working class has suffered the most from deindustrialization and social services defunding, which Trump has perfectly weaponized in his campaigns by promising a fictitious return to an equally fictitious past. You have lower wages? Blame it on the immigrants! No jobs? Blame it on non-whites!! And so forth.