Senator Marco Rubio (R., Fla.) told aides to “proceed” as if he is running for president, a revelation that comes just as he is set to join two other Tea Party senators with presidential ambitions at an economic policy forum this weekend.

Rubio, Senator Rand Paul (R., Ky.) and Senator Ted Cruz (R., Texas) will participate in a panel discussion moderated by ABC’s Jonathan Karl on Sunday. Governor Scott Walker (R., Wis.) will attend a seminar during the weekend conference.

“Our members care deeply about the future of our nation and we’re honored to host some of today’s most influential and respected leaders in shaping public policy,” James Davis, a spokesman for the Koch-backed Freedom Partners Chamber of Commerce, tells National Review Online. “We hope that this panel will give each participant the opportunity to lay out their vision of free markets and the role of government. Our goal in 2015 is to help inform the national debate around key domestic economic issues, and this forum is the beginning that conversation.”

Freedom Partners released a plan for economic growth that politicians might well look to as a blueprint for an agenda — especially if they hope for support from Freedom Partners Action Fund, which spent millions attacking Republican opponents in the 2014 elections.

The Rubio/Cruz/Paul event is a dramatic demonstration of a dynamic that has played out behind closed-doors in the Senate. As outsider candidates who pulled of upsets with the help of tea party activists, the trio went through an accelerated political coming-of-age: the moment they emerged as viable Senate candidates, the same national political appeal that brought them to that point made them possible presidential contenders. And because they were all Tea Party candidates, they were expected to be natural allies in the Senate — expectations that Cruz and Rubio fulfilled, at least partially, with their support for Rand Paul’s NSA filibuster.

The senators drifted apart, most notably when Rubio joined the Gang of Eight immigration group. Cruz opposed the bill, while Paul kept quiet on it, for the most part. That effort may have tarnished Rubio’s appeal among Tea Party activists, but it didn’t necessarily burn his bridges with the Koch allies. In fact, Charles Koch sponsored an “immigration summit” that immigration hawks regarded as stacked in favor of amnesty.