The start of an election campaign in America can be as much as one year before the actual election. When both Presidents Carter and Reagan decided that they would run for presidency both left their positions as governors and campaigned for a year before the election to work out grass roots support for them and to spread their ‘gospel’. It worked as both were elected. George W Bush and Al Gore started effective campaigning in January 2000 for a November election.
George Bush for the 2000 campaign continued to be governor of Texas but spent most of his time on the campaign trial. His one notable ‘event’ during the 2000 campaign as governor was his refusal to commute the death sentence on a rapist/murderer who was duly executed on the authority of the state’s governor. The Democrats responded with the "15 minutes" tag whereby they criticised the governor (to-be-president) on his record of deciding on a commutation of the death sentence or the execution being carried out: it was claimed that Bush Junior took only 15 minutes to decide the fate of a condemned man and that he was pandering to the belief in the South (a vital electoral region) that judicial execution was acceptable.
Officially an election campaign starts in February with the presidential primaries in the so-called "primary season". It continues from here. The key month for when party wards, precincts and states vote for their presidential candidate is March which includes "Super Tuesday". By then it is likely that those who had forwarded themselves for the party nomination for presidency will know if there is sufficient support for them within the party for them to proceed. Many will have drained their finances sufficiently to lead to them pulling out of the campaign.
This is how the campaign runs using the Democratic Party as an example :Wards X, Y Z etc. vote for their presidential nomination for the town/city of Tahoe, California. Delegates, to represent their views at the party's state convention, are also elected. This is usually done only by active and registered party members.
It is not as clear cut or as simple as this.Each ward can use its own system of voting for delegates and presidential nomination. This is not standardised throughout America and is symptomatic of the democracy that is meant to seep throughout politics right down to grass roots level. The theory is "why should regional party ‘big-wigs’ dictate to us how we should run our local party structure?".
This requires much travelling throughout the states and therefore a presidential candidate must have sufficient funds to see through a campaign. Winning the hearts and minds of local party activists is vital for a presidential candidate to proceed. They will vote for a candidate who has charisma and political know-how.
In the 1996 election the former Chief of Staff, Colin Powell, who had made his name during the Gulf War, was expected by the media to announce his intention to run for the presidency. However, Powell did not do this despite his popularity amongst the public simply because he, by his own admission, did not possess sufficient political know-how; something that can only be gained with years of political service (though to some extent J F Kennedy bucked this trend).