Trump, Cruz work to block Kasich from ballot at open convention

While Trump and Cruz are locked in a bitter battle, aides to both men tell msnbc it is in their mutual interest to keep Kasich off the ballot. The convention rules control who is on that ballot — and thus eligible to win the nomination.

“I expect the Rules Committee to require a level of support that would leave only two candidates on the ballot at the convention,” a senior Cruz Campaign aide told msnbc.

That committee, which writes the rules governing an open convention, is made up of 112 Republican delegates from around the country. Operatives for Cruz and Trump say they will have major sway over what the committee does.

“The Cruz people and Trump people are fighting hard to make sure their hard-core delegates get on the committee,” said Barry Bennett, a Trump adviser.