“Some policy makers are calling for piecemeal changes — such as issuing visas for high-skilled workers and investors, or conferring legal status on immigrants who were illegally brought to the country as children,” Bush wrote in an op-ed for The Wall Street Journal. “Congress should avoid such quick fixes and commit itself instead to comprehensive immigration reform…

Rubio is the most prominent advocate on Capitol Hill for a piecemeal approach to passing immigration reform legislation, a strategy that has yet to win the support of Sen. John McCain (R-Ariz.), a leading authority on the issue, or Democratic leaders…

John Weaver, a Republican strategist who worked for McCain’s 2000 and 2008 presidential campaigns, doubts Bush and Rubio will square off against each other in four years.

“I don’t know if there’s rivalry there yet. You have someone who would be the frontrunner in Bush and you have someone who is very ambitious and in his shadow and wanting to position himself for a run if he could,” he said. “That could cause some friction among staff.

“I don’t sense a rivalry. If Jeb Bush runs, Marco can’t run,” he added.