Republicans could be looking at a contested convention for the first time in 40 years. What happened the last time there was no clear winner heading into the convention? Well, mayhem didn't break out, but CNN's Brian Rokus reports it was a nail biter:

It was 1976 and a former California governor named Ronald Reagan wasn't just taking on the Republican establishment, he was taking on a sitting Republican president: Gerald Ford. And he was close to succeeding.

As the convention began in Kansas City, the presence of uncommitted -- and unpredictable -- delegates meant that nobody could tell which candidate was actually in the lead. The New York Times projected Ford with a lead of 39 delegates, while Reagan's campaign claimed he was ahead by 10. Both leads were minuscule given the 2,259 total delegates attending the convention.

Ford turned to James Baker, the man that would go on to be Secretary of State but in 1976 had one job -- get Ford the delegates he needed:

As the 1976 convention approached, Baker began tracking every single one of the approximately 150 uncommitted delegates, those who weren't already bound to vote for either Reagan or Ford. Baker and his team created dossiers on each of them.

"You need to know everything there is to know about a potential delegate ... what turns them on, what turns them off, what they believe in, what they favor, what they disfavor, who they're sleeping with," Baker said.  

Trump may indeed fall short of the full majority needed to win ahead of the convention, and if he does he will need to woo delegates, something his campaign has not been doing thus far.

As for Trump's claim that he should win if he simply has the most delegates, Baker said that's not how it works:

"That's a very good political argument for him to make, but that's not actually the way the process is supposed to work. It's supposed to work in a vote, or a series of votes by the delegates on the floor of the convention. They select the nominee. It is, after all, a party's nominating convention," Baker said.  

The Republican convention takes place July 18-21 in Cleveland, Ohio