One summer afternoon in 2013, Marco Rubio arrived at Mike Lee’s Senate office for a strategy session on derailing the implementation of the Affordable Care Act. Waiting inside were some of the upper chamber’s most conservative members, along with a group of influential activists. It promised to be an awkward pow-wow for the Florida senator, who had spent the 113th Congress authoring and promoting an immigration bill that turned some of his staunchest supporters — including some of those gathered in Lee’s office — into disgruntled opponents. Unperturbed, Rubio flashed a boyish grin and, according to multiple people present, greeted the group with a declaration: “The prodigal son is here.”
He knew he had sinned in their eyes, and that he needed the leaders of the increasingly powerful conservative movement that had championed his insurgent Senate bid to forgive him if he hoped to win their support for an eventual White House run. Yet one person in the room was already working overtime to make sure that wouldn’t happen. Ted Cruz, having copied Rubio’s anti-establishment blueprint to win his own Senate seat in 2012, had since usurped Rubio’s standing as the Tea Party’s favorite senator — in no small part by becoming the most vocal antagonist of the immigration-reform package that had blown up in the Floridian’s face earlier that summer. Both young senators harbored presidential ambitions, and if they ran against each other, Cruz wanted a clear contrast drawn between his brand of uncompromising ideological warfare and Rubio’s more pragmatic conservatism.