In 1968, the Nixon-Agnew ticket faced two principal opponents. The Democrats, at a convention marred by violent demonstrations, had nominated Vice President Hubert Humphrey and Maine Senator Edmund Muskie as their standard-bearers. The segregationist former Governor of Alabama, George Wallace, ran as a third-party candidate, and was expected to do well in the Deep South. Nixon, mindful of the restrictions he had labored under as Eisenhower's running mate in 1952 and 1956, was determined to give Agnew a much freer rein and to make it clear his running mate had his support. Agnew could also usefully play an "attack dog" role, as Nixon had in 1952.