A memo prepared for the group zeroes in on ballot access as a looming obstacle for any independent candidate, along with actually identifying a viable, widely known contender and coalescing financial support for that person. The two states with the earliest deadlines for independent candidates, Texas and North Carolina, also have some of the highest hurdles for independents to get on the ballot, according to the research.

“All this research has to happen before March 16, when inevitably Trump is the nominee, so that we have a plan in place,” a source familiar with the discussions said. March 16 is the day after the GOP primary in Florida, a winner-take-all contest that Marco Rubio supporters have identified as a must-win to stop Trump’s early momentum.

“It’s critical some serious attention is given to this,” the source said.

The document, stamped “confidential,” was authored by staff at Data Targeting, a Republican firm based in Gainesville, Fla. The memo notes that “it is possible to mount an independent candidacy but [it] will require immediate action on the part of this core of key funding and strategic players.”