Ted Cruz has repeatedly said that by rule only he and Donald Trump will be eligible to be on the ballot for consideration at a contested convention. Not necessarily.

The rule cited by Cruz — which requires that a candidate win a majority of delegates in at least eight states — was added as a temporary measure in 2012. Delegates for the 2016 convention could amend that rule, or waive it entirely.

Cruz has repeatedly cited the rule to label Ohio Gov. John Kasich a spoiler. Cruz says that by rule Kasich’s name cannot be placed in nomination and voted on at the Republican convention in July.

If Kasich fails to win eight states — a likely scenario — then that’s true under the rule as it stands today. But experts told us that rule could be amended. In recent conventions prior to 2012, the threshold was a plurality of delegates in five states. It had been three states prior to that, and in elections prior to the 1960s, there was no rule like that at all.

The issue of “Rule 40” has taken on heightened interest and scrutiny as a contested convention remains a possibility. Only Trump and Cruz have a mathematical chance at this point of winning a majority of delegates needed to secure the nomination on a first ballot. Kasich, who has won only his home state of Ohio, has pinned his presidential hopes on none of the candidates reaching the majority threshold, and then making his case at a contested convention.

Cruz has repeatedly argued in the last week, however, that Kasich would be precluded from nomination, by rule.

Cruz is referring to Rule 40 (b), which was adopted by the 2012 Republican National Convention. It required presidential candidates to have won a majority of delegates in at least eight states in order to be considered for nomination at the convention. The rule was proposed by supporters of Mitt Romney to block Ron Paul supporters from placing Paul’s name in nomination at the convention.

Trump is the only one to have reached that eight-state threshold so far. Cruz currently does not meet the benchmark, but he is well-positioned to do so by the convention, Josh Putnam, a lecturer at the University of Georgia who tracks delegate rules at the blog FrontloadingHQ, told us in a phone interview. It appears unlikely that Kasich will reach the eight-state threshold.

At a CNN town hall on March 29, Cruz claimed that “it’s against the rules for John Kasich to be on the ballot” and that “the only two names on the ballot are going to be Donald Trump and me. On the rules, those are the only two people that can be voted on.”

In an interview with Sean Hannity on Fox News on March 28, Cruz also asserted (at the 7:32 mark) that “under the rules, there will be only two names on the ballot, Donald Trump’s and mine.”

Kasich’s campaign disagrees. In a conference call on March 29, the Kasich team said it did not see the 2012 rule as a major obstacle, according to a report from National Review.

National Review, March 29: On the call, Kasich’s team also stated that Rule 40, which requires a candidate to have won a majority of delegates in eight states in order to be eligible to win the nomination, would not be a barrier for Kasich because the Rules Committee will meet anew to determine the rules for Cleveland.

Morris Fiorina, a political science professor at Stanford University, told us via email that the rule “can be changed by the convention at will.”

Prior to 2012, the rule read like this in 2008:

Rules of the Republican Party, 2008, Rule 40: (b) Each candidate for nomination for President of the United States and Vice President of the United States shall demonstrate the support of a plurality of the delegates from each of five (5) or more states, severally, prior to the presentation of the name of that candidate for nomination.

But in 2012, when Ron Paul secured the loyalty of enough delegates to flirt with meeting that threshold, the rule was amended — at the direction of supporters of Mitt Romney — to keep Paul’s name from being placed in nomination.

In 2012, the delegates changed the required threshold from a plurality of the delegates in five states to a majority of delegates in eight states.

Rules of the Republican Party, 2012, Rule 40: (b) Each candidate for nomination for President of the United States and Vice President of the United States shall demonstrate the support of a majority of the delegates from each of eight (8) or more states, severally, prior to the presentation of the name of that candidate for nomination.

In 2012, Rule 40 was expressly tagged as a “temporary” rule. As it states in Rule 42, “Upon the adoption of the report of the Convention Committee on Rules and Order of Business, Rule Nos. 26-42 shall constitute the Standing Rules for this convention and the temporary rules for the next convention.”

There will be numerous opportunities for delegates to rewrite rules prior to the 2016 convention.

In an interview with USA Today on March 23, Reince Priebus, chairman of the Republican National Committee, said likely there will be some rule changes.

“It’s … kind of silly to believe that the Romney delegates would write the rules for a convention in 2016 that, at this point, would be made up mostly of (Texas Sen. Ted) Cruz and Trump delegates,” Priebus said. “The delegates are the delegates won by the people that are being bound by the decision of the delegates.”

Priebus added, however, that he thought it was unlikely the delegates would alter Rule 40.

“I haven’t heard a whole lot of horsepower out there looking for a change on the rule,” Priebus says. “A few people speaking out in the wilderness, but the truth is there is no, at least at this point, groundswell to start changing the rules at the convention.”

Typically, rules are carried over from convention to convention, Putnam, told us. But the threshold for nomination eligibility has evolved over the last few decades.

“There might be a new version written by the rules committee,” Putnam said, which would then need to be voted on by all of the delegates to the convention. In the 1960s, a rule was added to require nominees to obtain a plurality of delegates in at least three states, as a way to limit the number of people whose names could be placed into nomination. The threshold was later upped to a plurality of delegates in five states.

Putnam believes it will be difficult to change the rule, given that most of the delegates are likely to be supporters of Trump or Cruz and would have a vested interest in keeping the rule as it stands to prevent consideration of another candidate.

At the Republican National Committee winter meeting in Charleston, South Carolina, there was some discussion of lowering the threshold to candidates who have received just one delegate. But the discussion was tabled, and there did not appear to be widespread support for it, Putnam said.

But that doesn’t mean it won’t be changed. Indeed, Politico reported that all four early appointees to the rules committee for this year’s Republican National Convention indicated they were “prepared to weaken or scrap a rule that could limit the convention’s alternatives to Donald Trump.”