Party leaders and activists and interest groups closely linked with the party are watching carefully as well. They want to determine which candidates would best serve their interests. In most presidential races until recent years, voters in the primaries and caucuses have nominated the consensus choice of the party’s leaders and activists. Rioters fought with police in the streets outside the 1968 Democratic convention. The party was torn by disputes over civil rights and American involvement in the Vietnam War. When the convention nominated the party leaders’ choice, Vice President Hubert Humphrey, as the Democratic presidential candidate, antiwar Democrats protested that the nomination did not fairly reflect the views of most grassroots party activists. The results dramatically transformed the process by which the Democrats select their presidential nominees. Each state decides whether to choose its delegates to the parties’ national conventions in a primary election or a series of caucuses.