Throughout the 19th and 20th centuries, Democrat and Republican primaries were beauty contests for presidential candidates. Most people didn't vote in them, and candidates were chosen at summertime party conventions, often in smoke-filled rooms by power brokers from various parts of the country.
After 1968, when the Democrats chose Hubert Humphrey as their standard-bearer, who had not run during the primaries, both parties changed their rules. Since 1972, primaries have become the way parties to choose their nominee, allowing voters in each state to voice their opinion.
Fast-forward to 2016. Political observers say the Republican party may be stuck with a divisive front-runner – Donald J. Trump. But the option of trying to wrestle away the party's nomination at the convention could backfire.
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Experts say taking the nomination away from Trump could lead to charges that the nominee doesn't represent the will of GOP voters who went to the polls during the primary election. That, in turn, could lead to Trump running as an third-party independent that would further split GOP voters into factions, thereby leading to a Democratic victory.
Could it even happen?
Political experts say that while legal, it would be difficult to get delegates to switch their votes to another candidate at the convention. Many states have laws that require the delegates to vote for their candidate during the first ballot.
"Think of it like an auction," said David Lublin, professor of government at American University in Washington who teaches a course on electoral politics. "If Cruz, Rubio and everyone together have less money (or delegates) than Donald trump, they can't win. They could persuade Trump's delegates to defect, but Trump and his people would cry bloody murder."
The question may hinge on exactly who gets selected as a delegate, and whether they are actually supporters of Trump or not. Only 27 percent of the named delegates are selected during the primary voting, the vast majority are picked at state party conventions later this year, usually for their loyalty.
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In that case, there could be big fights at the state party conventions, which are often held in June and July.
"You could have a lot of people who are selected by delegates who are bound by the state voting rules to vote for Trump, but may not be a Trump supporter themselves," said Kyle Kondik, managing editor of the political newsletter "Sabato's Crystal Ball" at University of Virginia Center for Politics. Kondik said there is some debate over whether state laws that force delegates to vote for their candidate on the first ballot are constitutional – a legal twist that may become more important down the road.
"There could be a whole set of politicking over who gets selected to be a delegate," Kondik said. "The Trump campaign doesn't have a good a grasp on that stuff as others do."
Both Lublin and Kondik agreed that if Trump achieves the magic number of 1,237 delegates, which is the majority, it will be difficult for the others to take away the nomination. But they noted that this primary season has been like no other in the past.
"There's no modern precedent for convention beyond a first ballot," Kondik said. "But if we go to [the Republican Convention in] Cleveland and nobody has a majority and they go beyond a first ballot, its possible that anything goes. Eventually the convention could nominate someone who has not participated in the primaries."