JetBlue will face "an uphill battle" as it fights the government," said Diana Moss, president of the American Antitrust Institute.
"If I'm JetBlue, that's where I focus right now, developing that divestiture offer and lining up a buyer to 'litigate the fix,'" said Dryden.
Whatever arguments JetBlue uses, a court fight could last six to eight months and cost tens of millions of dollars in attorney fees, legal experts said.
Bill Baer, head of the Justice Department's antitrust division under former President Barack Obama, said the government's complaint "shows that there is meaningful competition between Spirit and JetBlue."
"JetBlue brags about the 'JetBlue effect,' where they enter a market and fares tend to go down," he said.