Both Trump and Cruz showed this week that they are no longer going to exclude Kasich from the mud-slinging, which forces the Ohio governor to decide aggressive to get in his own defense.
"When he was congressman, he was a tough, hard-nosed congressman," said Tom Ingram, a senior campaign adviser. "That is the Kasich that we need to see. I don't want him fighting with the guys. I want him competing with them, particularly Cruz."
Though plans remain as fluid as the race itself, campaign insiders agree Kasich's best, if not only, shot at the nomination would be on a theoretical third ballot at the convention.
RNC rules stipulate that most of the delegates are bound on the first ballot of the convention. One third remain bound on the second ballot. The third ballot would find the lion's share of delegates left to their own devices. If it comes to a fourth ballot, however, the assumption is that delegates might be looking for an entirely fresh option, such as Ryan. (Schrimpf said he doesn't expect Ryan or any "white knight" candidate to ultimately get the nomination.)
Ingram said the campaign has been in frequent discussions with delegates who are bound to Rubio on the first ballot; he thinks at least half of them could flip to Kasich by the third ballot. Kasich's delegate czar is Charlie Black, a deeply connected Republican operative who advised the presidential campaigns of George W. Bush, John McCain and Mitt Romney. It will be among his jobs to persuade the rules committee to preserve Kasich's eligibility.
In the interim, Schrimpf said, "Everybody needs to calm down and wait for the rules committee to make the rules and know that, even when they make the rules, those rules can be changed at any point int he convention."