In a new administration where the president can take on any government program in a 140-character criticism for all to see, experts say back-room meetings that have dominated D.C. will become less important as defense industry is forced to make their case to the public.

President-elect Trump took on two high-cost Pentagon programs on Twitter late last year, slamming the "out of control" cost of Lockheed Martin's F-35 and threatening to cancel the government's order for two new Boeing Air Force One planes. Both tweets drew personal commitments from the companies' CEOs to cut costs.

Trump also announced on Twitter that he had asked Boeing to "price out" a version of its F/A-18 Super Hornet that would be "comparable" to the F-35, creating a real impact on the stock market within a matter of hours.

Todd Harrison, the director of defense budget analysis at the Center for Strategic and International Studies, said this reality is forcing the industry to "fundamentally change" its government relations and lobbying for at least the next four years.

Today, when a company wants to ensure a program stays on track, they dispatch lobbyists to the administration, Pentagon and Capitol Hill to sing the praises of their platform behind closed doors, Harrison said. But when Trump can and is communicating directly with the public, the case lobbyists can make to lawmakers privately becomes less important.

"Now, they run into a situation where the president could come out on Twitter and go directly to the public and publicly shame them for something that may or may not be true," he said. "All of this back-room lobbying and debate and discussion may not help them anymore if they're being publicly shamed."

"I think that lobbyists are going to have to come out of the shadows," Harrison continued. "That also means that behind-closed-door lobbying is probably going to be of less importance in the future and public messaging and rapid reaction, or public relations efforts are probably going to grow in importance."

Marc Numedahl, vice president of Capitol Strategies Partners lobbying firm, said companies are working to protect themselves should they find one of their programs in Trump's crosshairs, but noted that industry is always ready to defend its programs to powerful stakeholders and that many of the tools to do so haven't changed.

"Almost every company that has a major acquisition program is setting up kind of a rapid response plan to a potential Trump tweet or mention, but … other than the unpredictability of when it could happen, I don't think they view it as responding to Trump as any different than responding to any other powerful stakeholder that might have a problem with their program," he said.

Numedahl also said it's important for lobbyists to maintain relationships with allies on Capitol Hill and the Pentagon because Trump appears to listen to retired Gen. James Mattis, his pick to lead the Pentagon.

Since reducing defense costs is a key priority for Trump, Byron Callan, an analyst at Capital Alpha Partners, said it's important for the incoming president to learn why defense procurement costs so much in the first place. While some costs undoubtedly come from waste and bureaucracy, Callan pointed out that the military is buying some very advanced systems with high-end capabilities.

"These are highly complex advanced weapons systems," he said. "They're not buying stuff from Target or Sears. There's a price to pay."

As a result, he stressed the importance of getting someone in the deputy defense secretary job who has a background in industry and can explain why the cost of these systems is so high. Mattis likely won't excel at this because of his background as a warfighter, Callan said.

"He's always operated at the pointy end of the spear, he hasn't been in the workshop where the spears are made," Callan said. "He'll certainly have an understanding of how to use those things, when to use them and when not to use them."