Houston (CNN) Marco Rubio 's campaign is preparing for a contested Republican Convention as one option to take the GOP nomination away from Donald Trump and Ted Cruz , his campaign manager told top donors at a closed-door meeting in Manhattan Wednesday night.

As Rubio scrambles for support ahead of Super Tuesday , Terry Sullivan, Rubio's top adviser, used a Power Point presentation and took questions from attendees to lay out the two courses that Rubio's quest for the GOP nomination could take in the coming months, two people present told CNN, speaking anonymously to share details from a private meeting.

Hillary Clinton launched her presidential bid on April 12 through a video message on social media. The former first lady, senator and secretary of state is considered the front-runner among possible Democratic candidates."Everyday Americans need a champion, and I want to be that champion -- so you can do more than just get by -- you can get ahead. And stay ahead," she said in her announcement video. "Because when families are strong, America is strong. So I'm hitting the road to earn your vote, because it's your time. And I hope you'll join me on this journey."

Ohio Gov. John Kasich joined the Republican field July 21 as he formally announced his White House bid. "I am here to ask you for your prayers, for your support ... because I have decided to run for president of the United States," Kasich told his kickoff rally at the Ohio State University.

Ohio Gov. John Kasich joined the Republican field July 21 as he formally announced his White House bid. "I am here to ask you for your prayers, for your support ... because I have decided to run for president of the United States," Kasich told his kickoff rally at the Ohio State University.

Sen. Ted Cruz of Texas has made a name for himself in the Senate, solidifying his brand as a conservative firebrand willing to take on the GOP's establishment. He announced he was seeking the Republican presidential nomination in a speech on March 23."These are all of our stories," Cruz told the audience at Liberty University in Virginia. "These are who we are as Americans. And yet for so many Americans, the promise of America seems more and more distant."

Businessman Donald Trump announced June 16 at his Trump Tower in New York City that he is seeking the Republican presidential nomination. This ends more than two decades of flirting with the idea of running for the White House."So, ladies and gentlemen, I am officially running for president of the United States, and we are going to make our country great again," Trump told the crowd at his announcement.

The first showed the number of states and delegates Rubio would need to clinch the nomination outright before July's convention. The second was the scenario in which none of the candidates gain the simple majority delegates needed to clinch the nomination before the convention, unleashing a messy and potentially unpredictable battle where multiple candidates are vying for the title.

The meeting comes as Rubio is trying to lock up the support of establishment Republicans looking for an alternative to Trump and Cruz. The Rubio campaign needs to convince donors and GOP power brokers that it has a true path to victory. Trump is heading into Super Tuesday as the undisputed GOP front-runner, having won New Hampshire South Carolina and Nevada , and Rubio has not yet won a state.

Sullivan has acknowledged in the past that a brokered convention might be hypothetically possible, but Wednesday's comments are a concrete indication that the campaign is preparing for such an outcome.

Sullivan gave a "technical" explanation of how a contested or brokered convention would work. According to the sources in the room, the gathering appeared to be a matter-of-fact recognition by the Rubio campaign that a contested convention is very much a possibility.

"One is somebody -- Trump or Rubio -- wins enough primaries to sew up the nomination in advance of the convention," one attendee said. "The other is that nobody does, and the two candidates go to the convention."

Photos: Can you guess the 2016 contenders' campaign logos? Photos: Can you guess the 2016 contenders' campaign logos? Hide Caption 1 of 41 Photos: Can you guess the 2016 contenders' campaign logos? Hide Caption 2 of 41 Photos: Can you guess the 2016 contenders' campaign logos? Former Gov. Jeb Bush, R-Florida Hide Caption 3 of 41 Photos: Can you guess the 2016 contenders' campaign logos? Hide Caption 4 of 41 Photos: Can you guess the 2016 contenders' campaign logos? U.S. Sen. Marco Rubio, R-Florida Hide Caption 5 of 41 Photos: Can you guess the 2016 contenders' campaign logos? Hide Caption 6 of 41 Photos: Can you guess the 2016 contenders' campaign logos? Former Secretary of State Hillary Clinton, Democrat Hide Caption 7 of 41 Photos: Can you guess the 2016 contenders' campaign logos? Hide Caption 8 of 41 Photos: Can you guess the 2016 contenders' campaign logos? U.S. Sen. Bernie Sanders, independent from Vermont running for Democratic nomination Hide Caption 9 of 41 Photos: Can you guess the 2016 contenders' campaign logos? Hide Caption 10 of 41 Photos: Can you guess the 2016 contenders' campaign logos? Real estate mogul Donald Trump, Republican Hide Caption 11 of 41 Photos: Can you guess the 2016 contenders' campaign logos? Hide Caption 12 of 41 Photos: Can you guess the 2016 contenders' campaign logos? U.S. Sen. Ted Cruz, R-Texas Hide Caption 13 of 41 Photos: Can you guess the 2016 contenders' campaign logos? Hide Caption 14 of 41 Photos: Can you guess the 2016 contenders' campaign logos? John Kasich, R-Ohio Hide Caption 15 of 41 Photos: Can you guess the 2016 contenders' campaign logos? Hide Caption 16 of 41 Photos: Can you guess the 2016 contenders' campaign logos? Retired neurosurgeon Ben Carson, Republican Hide Caption 17 of 41 Photos: Can you guess the 2016 contenders' campaign logos? Hide Caption 18 of 41 Photos: Can you guess the 2016 contenders' campaign logos? U.S. Sen. Rand Paul, R-Kentucky, who has dropped out of the presidential race. Hide Caption 19 of 41 Photos: Can you guess the 2016 contenders' campaign logos? Hide Caption 20 of 41 Photos: Can you guess the 2016 contenders' campaign logos? Former U.S. Sen. Rick Santorum, R-Pennsylvania, who has dropped out of the presidential race. Hide Caption 21 of 41 Photos: Can you guess the 2016 contenders' campaign logos? Hide Caption 22 of 41 Photos: Can you guess the 2016 contenders' campaign logos? Former Gov. Rick Perry, R-Texas, who has dropped out of the presidential race. Hide Caption 23 of 41 Photos: Can you guess the 2016 contenders' campaign logos? Hide Caption 24 of 41 Photos: Can you guess the 2016 contenders' campaign logos? Former Gov. George Pataki, R-New York, who has dropped out of the presidential race. Hide Caption 25 of 41 Photos: Can you guess the 2016 contenders' campaign logos? Hide Caption 26 of 41 Photos: Can you guess the 2016 contenders' campaign logos? Former Gov. Mike Huckabee, R-Arkansas, who has dropped out of the presidential race. Hide Caption 27 of 41 Photos: Can you guess the 2016 contenders' campaign logos? Hide Caption 28 of 41 Photos: Can you guess the 2016 contenders' campaign logos? Former Gov. Martin O'Malley, D-Maryland, who has dropped out of the presidential race. Hide Caption 29 of 41 Photos: Can you guess the 2016 contenders' campaign logos? Hide Caption 30 of 41 Photos: Can you guess the 2016 contenders' campaign logos? Former Hewlett-Packard CEO Carly Fiorina, Republican, who has dropped out of the presidential race. Hide Caption 31 of 41 Photos: Can you guess the 2016 contenders' campaign logos? Hide Caption 32 of 41 Photos: Can you guess the 2016 contenders' campaign logos? U.S. Sen. Lindsey Graham, R-South Carolina, who has dropped out of the presidential race. Hide Caption 33 of 41 Photos: Can you guess the 2016 contenders' campaign logos? Hide Caption 34 of 41 Photos: Can you guess the 2016 contenders' campaign logos? Former U.S. Sen. Lincoln Chafee, D-Rhode Island, who has dropped out of the presidential race. Hide Caption 35 of 41 Photos: Can you guess the 2016 contenders' campaign logos? Hide Caption 36 of 41 Photos: Can you guess the 2016 contenders' campaign logos? Wisconsin Gov. Scott Walker, Republican, who has dropped out of the presidential race. Hide Caption 37 of 41 Photos: Can you guess the 2016 contenders' campaign logos? Hide Caption 38 of 41 Photos: Can you guess the 2016 contenders' campaign logos? Former U.S. Sen. Jim Webb of Virginia, Republican, who has dropped out of the presidential race Hide Caption 39 of 41 Photos: Can you guess the 2016 contenders' campaign logos? Hide Caption 40 of 41 Photos: Can you guess the 2016 contenders' campaign logos? Louisiana Gov. Bobby Jindal, Republican, who has dropped out of the presidential race Hide Caption 41 of 41

On how Rubio could get the nomination before the convention, Sullivan discussed the possibilities of John Kasich and Ben Carson dropping out, that attendee also said.

Rubio spokesman Alex Conant declined to comment. Sullivan did not immediately respond to a request for comment.

Sullivan also expressed confidence that Rubio would win the Florida primary, two attendees said, despite polling showing Rubio trailing Trump in his home state.

There were close to some 200 people present at the midtown Manhattan meeting -- and among them were former Jeb Bush supporters, the people present said.

Coming just days after Bush abandoned his White House bid, one question from these donors and potential bundlers -- not all of whom had decided to back Rubio -- was whether the Rubio team could reassure them that their money and time would not once again go to waste, according to one attendee.

"They wanted to know that we on the Rubio side are going to be good stewards," the person said.