The 2016 RNC convention in Cleveland is only three months away, but it is perhaps a rule used in 2012 that will have the greatest impact in Ohio.
In 2012, Republicans were worried about Ron Paul's popularity possibly upsetting establishment candidate Mitt Romney's clear path to the nomination. So, the RNC Rules Committee changed the rules.
Whereas previous conventions allowed for any candidate with the largest share of delegates in at least five states to be placed on the ballot, Republicans raised the 2012 threshold to eight states and the candidate needed a majority of delegates in the contests, not just the largest share.
What this meant was that Paul, whose supporters successfully played the delegate game in many states, could not upset Romney's nomination bid. Paul's name would not appear on the ballot because he didn't reach the eight-state threshold. This rule will likely have a great impact in 2016 also.
The irony of what is now colloquially called the "Ron Paul Rule" is that this year, the higher threshold might hurt party attempts to undermine the anti-establishment front-runner, Donald Trump.
Trump currently holds 846 of the required 1,237 delegates needed to ensure his nomination with 15 states still left to vote. Even if he falls short, Ted Cruz and John Kasich both are at risk of not even making the eight-state majority minimum if the rule stands.
Currently, Ted Cruz has won at least a plurality of the primary or caucus vote in 9 states, but only took a majority of the delegates in 6 of those states. Colorado, which didn't have a presidential preference election of any kind this year, and Wyoming's delegates were given to Cruz at the states' party conventions, which the Rules Committee could argue brings Cruz to the eight-state threshold.
However, how the state party handled the delegate process in Colorado is the subject of heated controversy, with Trump calling the process 'rigged,' and most Republican voters were locked out of the process altogether.
Kasich on the other hand has only managed to win his home state. His second place finishes in various states would have no bearing on being able to appear on the ballot under this rule.
The fight over the nomination could ultimately rest on whether the RNC upholds the 2012 rule for this year's convention. Therefore, what is formally known as Rule 40B in the Republican Nomination Rule Book is gradually gaining public interest.
It is important to note that all rules on the book are noted as "temporary" and therefore, the Rules Committee could easily decide to change Rule 40 to lower the number of states needed, replace majority with plurality win, or even repeal it all together to set up a fierce battle at the convention.
Ben Ginsburg, an RNC member who helped write Rule 40, as well as other RNC committee members have stressed the temporary nature of any rules until they are approved by this year's convention, meaning that no one really knows what the final rules for the 2016 convention will look like until the eve of the convention.
What is certain, however, is that with both parties fractured and no clear winner in either one as of mid-April, both the Republican and Democratic conventions will be highly contested and politically intriguing events this summer.