Short's move to the Rubio team, where he is expected to serve as senior adviser, was first reported by Politico.
"Marc has been a valued leader and contributor to Freedom Partners and our network's success for the past five years," said Mark Holden, general counsel of Koch Industries, who chairs the board of Freedom Partners. "We thank him for his dedicated service and wish him continued success in the future."
The Koch political network, which has set a goal of spending nearly $900 million in the run-up to the November elections, is not expected to jump into the GOP nomination contest as it currently stands. Among the hundreds of donors who contribute to the operation are supporters of both Rubio and Sen. Ted Cruz of Texas.