More than four times as many voters showed up to caucus as did in 2004 -- nearly 30,000, the Idaho Statesman reported. Obama captured 80 percent of the statewide vote, topping rival Sen. Hillary Clinton, D-N.Y., to win all of the state's 23 delegates to the Democratic National convention.

Obama supporters packed the Qwest Arena in Boise. Several thousand people were forced to wait outside as snow fell because the crowd exceeded the arena's 6,500 capacity.