In state after state, labor unions and community groups have pushed lawmakers to raise the minimum wage, but those efforts have faltered in many places where Republicans control the legislature.

Frustrated by this, workers’ advocates have bypassed the legislature and placed a minimum-wage increase on the ballot in several red states — and they are confident that voters will approve those measures on Tuesday.

In Alaska, Arkansas, Nebraska and South Dakota, binding referendums would raise the state minimum wage above the $7.25 an hour mandated by the federal government.

These measures are so overwhelmingly popular in some states, notably Alaska and Arkansas, that the opposition has hardly put up a fight.