Marco Rubio
Senator Marco Rubio (R-FL) addressed the International Association of Firefighters delegates at IAFF Presidential Forum in Washington, March 10, 2015. Rubio is expected to announce a run for president on Monday. Reuters

As U.S. Sen. Marco Rubio, R-Fla., gears up to announce what many expect to be his presidential bid Monday, a super PAC was set up Thursday that allows an outside group to raise unlimited funds for his campaign, the Associated Press reported. The super PAC, called Conservative Solutions, will mostly use the money to buy political ads.

Rubio has a “big announcement” planned for Monday at the Freedom Tower in Miami in what is likely a speech declaring his run for the Republican nomination for president. Rubio would be the third official GOP candidate in the race, following Republican Senate colleagues Ted Cruz of Texas’ announcement late last month and Rand Paul of Kentucky’s speech Tuesday. The Florida senator would become the first Hispanic president of the United States if he wins the GOP nomination and then defeats the Democratic nominee in the general election in November 2016.

Warren Tompkins, who was Ronald Reagan’s political director for the South Carolina presidential primary in 1980 and went on to work for George H.W. Bush and Mitt Romney’s campaigns, was tapped to head Conservative Solutions, according to the AP. "This race will be won by the candidate with the best vision for where to take this nation and the resources to ensure that message is heard," Tompkins said in a statement. "Marco has the vision -- few have laid out in as much detail where they'd like to lead this country -- and we're going to spend the next two years ensuring that the resources are there and used to effectively share that vision with voters."

Conventional wisdom was that Rubio would sit out 2016 in part because his political mentor, former Florida Gov. Jeb Bush, is likely running and has a vast database of donors and supporters from his father’s and brother’s campaigns that would be tough for Rubio to match. Bush is considered an early front-runner for the GOP nomination and Rubio running could be seen as an act of disloyalty by the former Florida governor.

The campaign accounts of presidential contenders are limited to raising a maximum of $2,700 from donors, but super PACs can raise unlimited funds. In 2012, the super PAC supporting President Barack Obama’s re-election raised $65 million while the super PAC aligned with GOP nominee Mitt Romney raised $142 million in an attempt to defeat Obama. Unlike traditional presidential campaign accounts, super PACs don’t have to disclose the names of donors.