Clinton grew her delegate lead last week with wins in Connecticut, Pennsylvania, Maryland, and Delaware. Sanders took Rhode Island.
With 64% reporting, Clinton has 47% while Sanders has 53%.
Whatever the results in Indiana, Sanders has an increasingly narrow chance of entering the Democratic Convention with enough pledged delegates to win the nomination. He has, however, vowed to remain in the race, saying that he hopes to win over superdelegates.
With 83 delegates up for grabs in Indiana, Clinton already has 1,645 pledged delegates, while Sanders has 1,318.
The next Democratic primary will be held in Guam on Saturday. Clinton hopes to hang onto her lead in upcoming primaries in Kentucky, Oregon, California, and New Jersey, among others. In the California, the largest delegate state, current polls show Clinton leading by nearly 10 points.
