Via FAS – CRS INSIGHT – Contested Presidential Nominating Conventions: Brief Background and Questions, April 15, 2016 (IN10478).

“Neither major party has required multiple votes to select a presidential nominee since the 1952 Democratic National Convention and the 1948 Republican National Convention. Yet, prolonged primary campaigns routinely fuel speculation that convention delegates might again be called on to choose a party’s presidential nominee through multiple ballots, rather than to ratify a clear outcome from the primaries. This CRS Insight briefly addresses selected questions about possible contested Democratic and Republican conventions that might be relevant as Members of Congress prepare for the 2016 election…”