What happens if, after months of presidential primaries and caucuses, a political party still can't pick a nominee? While no one can definitely predict what the end result will be for the current election season at the end of the primary calendar, this isn't the first time that pundits have asserted the possibility of a race being decided at a party's convention.
In 2008, for example, when the two major Democratic party nominees, Barack Obama and Hillary Clinton, were trading victories in primaries and caucuses and amassing delegates along the way, party leaders expressed concern about the possibility of a contested convention.
Rumors of the possibility of a brokered convention seem to arise every few election cycles. A brokered convention occurs when more than one candidate is still in the running following the party's primary process and hasn't secured enough delegates to win the nomination.
Delegates are allotted through victories in the primaries and caucuses. State parties have different rules for how delegates are apportioned. In other words, not only do Republicans and Democrats have different processes, but different states also have their own methods rewarding victories in primaries and caucuses.
Some states are "winner-take-all" contests, as was the case in the Florida and Arizona Republican primaries. In other states, delegates are allocated proportionally relative to the number of votes each candidate receives in the state. The recent Republican contests in Alabama and Mississippi, for example, were "proportional" primaries.
There are also different types of delegates, some of which aren't bound by the primary primary. Delegates are party leaders, activists and supporters who are chosen at the state's party convention. How the delegates themselves are chosen can vary by party, state and even congressional district. Delegates vote for their candidate on a ballot at the national convention.
No matter how a party nominee actually amasses delegates, in the case of both parties, the winner of the primary season is cemented when one candidate has amassed at least half of the total delegates available.
If a candidate can't reach that number through the primary process or after the first ballot at the national convention, then a "brokered convention" is what ensues, and that's when new possibilities arise in subsequent ballots. Delegates won during the primary process for the Republican nomination, for example, would be released from their obligation to vote for a particular candidate. A nominee would only be chosen after a candidate has won majority support, which can take many rounds of ballots in a particularly contested convention.
Since the 1952 Democratic National Convention in which the party chose Adlai Stevenson as its nominee, there hasn't been a single brokered convention. Prior to the introduction of the primary process in which ordinary voters had a say in their candidates, brokered conventions actually happened regularly. Since the inclusion of primary voting, the only convention that was seriously contested was in 1976 when incumbent President Gerald Ford barely held off a challenge from Ronald Reagan to win the party's nomination on the first ballot.
Photo: A top-down view of the floor during the Republican National Convention in 2008. Credit: Corbis Images