For the first time since 1948 a Republican incumbent faced a challenge for the nomination. Little known Illinois congressman John B. Anderson announced in June 1979 that he would challenge Reagan for the nomination. He immediately won the support of many liberal republicans. However Anderson's campaign lacked discipline and organisation, and he relied heavily on grassroots liberal-moderate support that always favoured the democratic party, particularly the Kennedies.
Reagan beat Anderson in Iowa, but his unconvincing showing of 57% was a set back. Anderson garnered 33% in Iowa, and in New Hampshire fought Reagan to an even narrower 55% - 45% margin. Anderson won in Massachusetts 51-49, and in Vermont lost to Reagan by the same margin.
However as the primary contests moved to the more conservative midwest Anderson's victories became fewer and fewer, and the nomination fell from his grasp.
Kennedy was - as he had been in 1972 and 1976 - the obvious front runner for the democratic nomination. Some expected Kennedy to refrain from contesting yet again, and prehaps allow California Governor Jerry Brown to lead the liberal banner. However Kennedy announced in September 1979 that he would seek the Democratic nomination.
John B. Anderson's bid to prevent a sitting President's renomination failed. But by the time he conceded defeat in May he had built up a large nationwide support base, and had the backing of a large number of more liberal republicans.
On May 31st Anderson announced he would run as an Independent candidate as a moderate alternative to the liberalism of Kennedy and the Conservatism of Reagan.
Kennedy - 46%
Reagan - 42%
Anderson - 12%