Primaries v caucuses in the Democratic presidential race

By The Data Team

BERNIE SANDERS enters today’s Democratic primary election in Wisconsin with the wind in his sails following his recent triumphs. But if he wins it will be only his fifth victory in a primary election; all his other successes, including his most recent, have been in states that hold caucuses, a more complex system for choosing delegates to the party’s national convention. Caucuses are local meetings of party loyalists that have much lower participation rates than primary elections. They also tend to be dominated by activists. In his recent caucus wins, Mr Sanders’s supporters have propelled him to huge margins of victories: 78% to Hillary Clinton’s 21% in Idaho, for example, and 73% to 27% in Washington state (on the Republican side, Ted Cruz has also had a better success rate in caucuses).