In a moment when the most credible left-wing presidential candidate in American history has become the frontrunner for the Democratic nomination, it’s difficult not to feel the absence of the labor movement from the effort. With some noteworthy exceptions — a few left-wing unions and some ideologically committed locals of unions that are neutral on the national level — organized labor has watched the Bernie Sanders campaign, with its acknowledgment of class conflict and its call for working-class victory, from the sidelines.

Now, as Sanders advances, it’s disturbing to see outright opposition emerge from a union with enormous influence in a key state, which has long been known as a beacon of militancy: Local 226 of Unite Here, otherwise known as the Culinary Workers Union of Las Vegas.

The Culinary has constructed in the Sun Belt desert something that seems to belong to another moment in history. It represents 60,000 hospitality workers across Nevada’s casinos, forming an enormous concentration of working-class power in the otherwise hostile territory of the low-wage service economy in a right-to-work state. It accounts for one-fifth of the entire membership of Unite Here, of which it is by far the largest and most internally important local. (The current president of Unite Here, D. Taylor, was previously the president of the Culinary.)