“They have no infrastructure,” said Scott Reed, who is unaffiliated with any campaign but serves as the chief political strategist for the U.S. Chamber of Commerce. “His campaign hasn’t been able to keep up with his candidacy. . . . They don’t have the operation in the states to help him get over the top. He should be a finalist going all the way to California, and he’s not.”
As I've said, there is more information than polling that SAVVY political analysts might be able to use. The fact that Rubio didn't actually run a campaign should have been a clue.