Kasich is looking to the traditional model. He is the compassionate conservative of 2016 who hopes to strike first in New Hampshire and build from there. His advisers believe that, eventually, he can reach across the divide in the party to become the nominee.

But the party has not only moved right in the past decade, it also has developed a harder edge than when George W. Bush ran as a compassionate conservative in 2000. Kasich’s support for expanding Medicaid under the Affordable Care Act is just one example of a position that will not sit well with many conservatives.

Rubio’s team sees crosscutting appeal as vital, a race that will favor a candidate who can best unite a fractured party. The senator’s goal is to demonstrate skills as a communicator, to show depth on the issues, to turn his personal story into a positive message for the party, to make as few errors as possible and over time generate enthusiasm across the GOP coalition.

Rubio, too, has vulnerabilities. His past support for a path to citizenship for undocumented immigrants, from which he has backed away, remains an obstacle in his path. So too does his personal profile, that of a youthful first-term senator with limited experience trying to become president — a profile not unlike that of President Obama when he first ran eight years ago.