Recently, presidential candidate Donald Trump has been riding a wave of voter frustration and anger. Trump's supporters are fed up, and they want change, without stopping to figure out first what change they would actually get if Trump was elected. The Republican party is alarmed at the prospect of a Trump candidacy, and is frantically looking for a Plan B. Since Trump has not yet won a majority of the 2,472 Republican delegates up for grabs, it is possible that even though he has more delegates than any other candidate so far, he might not be able to win enough support to clinch the nomination before the Republican convention opens. If Trump is unable to win enough delegates in the remaining Republican primaries, the result will be a brokered convention. At a brokered convention, anyone who wins a majority of the delegates will get the nomination, regardless of who the primary voters originally supported.
Brokered conventions used to be much more common than they are now, partly because backing by party leaders took precedence over primaries. In the Democratic party, a two-thirds majority was required to win nominations, while the Republicans required only a simple majority. If this majority was not reached on the first ballot, voting would continue, accompanied by party leaders' deal-making behind closed doors, until one candidate came up with enough support to win.
The last time a brokered convention resulted in a candidate that went on to become president was in 1932. That year, the Democratic convention opened with no clear winner. Franklin Roosevelt, the governor of New York, was one of the candidates. There were doubts that he would win. A famous political commentator described him as, “a pleasant man who, without any important qualifications for the office, would very much like to be president.” FDR's rivals included the Speaker of the House, John Garner of Texas, and Al Smith, who was considered unelectable because he was Catholic. Although short of the necessary two-thirds support, FDR eventually won the nomination by promising to make Garner his vice president, thus winning Garner's supporters. He went on to become the only president in history to win four terms.
In recent decades, party rules have been changed to give voters more control over who wins the Republican and Democratic nominations, making the chances of a brokered convention less likely than before. The magic number of delegates that a Republican candidate will have to win in order to clinch the nomination this year is 1,237. If no candidate wins this many delegates, the Republican nomination will be up for grabs for the first time since 1976. That means that the Republican convention this year might just be a little more interesting than usual.