North Carolina, Ohio, and other states have moved in recent years to cut early voting days or hours. That's a move that the GAO's 2014 report concluded was more likely to inconvenience black voters, who tend to favor early voting in person [sources: Wilson, GAO].
Limiting the number of polling places is another tactic. Arizona's Maricopa County, the state's major population center, offered 400 locations in 2008, but reduced that by half in 2012. In 2016, the county only provided 60 polling places for voters for the presidential primary. As a result, voters had to wait in line for as long as five hours in some places [source: Christie and Van Veltzer].
It's unclear just how many voters gave up and went home without voting as a result of the logjam. But one critic, U.S. Rep. Ruben Gallego, a Democrat, said that it disproportionately affected minorities and the working poor, who have a harder time finding transportation [source: Christie and Van Veltzer].