Most of the horrors assigned to fascists, as understood in the liberal canon, had precedents among liberal governments, often on much larger scales. Most genocides around the planet, and most people killed in genocide, were carried out by liberals in liberal democracy. They are the genocides of colonialism, including settler- colonialism, inckuding the genocide of indigenous Americans still in living memory. Nationalism is a liberal campaign, it emerges from capitalism and its primary ideology, and liberals celebrate it constantly. Scapegoating and creating marginalized groups has always been something liberals engaged in, though there has also always been a split between those they consider gauche and unacceptable (and they are the "good guys" for opposing) and those that they find acceptable (they are still the "good guys" for this), like their current siniphobia, russophobia, and islamophobia.

Point is, genocide is making a return in liberal discourse to being something they accept. They already did before and were very racist about it. They just took a break, at least in their PR, after they had their sole actual "good guy" war in WWII and needed to rhetorically distance themselves from Nazis and work around the popularity of the left in Europe after the defeat of the Nazis.