The Economist on US presidential candidate announcements: A history of hat throwing "Before the 1970s campaigns tended to be shorter. Candidates often threw their hats into the ring only a few months before election day. Campaigns grew longer after the Democrats re-wrote their party rules to give more weight to primary elections in the states rather than secretive negotiations at the nominating convention. This forced candidates to make their pitches directly to ordinary voters, which takes longer (see chart). The Republicans followed suit."