NYT: Southern black voters don’t usually play a decisive role in national elections. They were systematically disenfranchised for 100 years after the end of the Civil War. Since the days of Jim Crow, a fairly unified white Southern vote has often determined the outcome of elections.

This November could be different. Nearly five decades after the passage of the Voting Rights Act, black voters in the South are poised to play a pivotal role in this year’s midterm elections. If Democrats win the South and hold the Senate, they will do so because of Southern black voters.

This year’s closest contests include North Carolina, Louisiana and Georgia. Black voters will most likely represent more than half of all Democratic voters in Louisiana and Georgia, and nearly half in North Carolina. Arkansas, another state with a large black population, is also among the competitive states.

Southern black voters have already made their mark on this year’s midterm elections. Last month, Senator Thad Cochran defeated a Tea Party challenger with the help of a surge in black turnout in a Republican run-off in Mississippi.