If , after the first round of voting , there is no candidate with a majority of votes , subsequent roll calls are held . In between , " back room deals " can be made between candidates , swapping delegates for positions in the administration or other favors , or candidates can release their delegates to vote for whoever they personally prefer . Roll calls continue until one candidate has a majority . The record is held by the 1924 Democratic National Convention where divisions within the party concerning Prohibition led to 102 ballots between Alfred E. Smith and William G. McAdoo before the relatively unknown John W. Davis was chosen as a compromise candidate on the 103rd ballot
1924 Democratic National Convention
1924 Democratic National Convention
United States presidential nominating convention