Sen. John McCain’s (Ariz.) allies are defending the presumptive GOP presidential nominee from Democratic attacks stating that he single-handedly helped doom Boeing’s bid for a multibillion-dollar defense contract, which instead went to a U.S.-European team that included rival Airbus.  

McCain’s Hill supporters, along with independent watchdog organizations, warn that Democrats could be playing a dangerous game in criticizing McCain. They note his probe of the Air Force’s leasing deal with Boeing unearthed corrupt procurement practices that led to prison terms for a former top Air Force official and a Boeing executive.

At the same time, the Democratic attacks highlight areas where McCain could be vulnerable, particularly in battleground states such as Ohio, where arguments that candidates have backed policies at the expense of off-shoring U.S. jobs can resonate.

Several high-ranking House Democrats have charged that McCain is partly to blame for the Air Force’s surprise decision last week to award a contract worth as much as $40 billion to a team that includes Northrop Grumman and EADS, the parent company of Airbus.

They argue that McCain should not have pushed for a new bidding process five years ago that opened Boeing up to competition from Airbus after a deal in which Boeing would have leased tankers to the Air Force fell apart amid corruption charges. The unraveling of that deal led to the competition won by the U.S.-European partnership last week.

“He could have reformed the contract that Boeing got rather than reopening it and sending the jobs to France,” said a critical Rep. Rahm Emanuel (Ill.), the chairman of the House Democratic Caucus.

After the tanker leasing deal collapsed and a new competition started, Boeing’s supporters say McCain intervened again — to the detriment of Boeing. They say he pressed the Pentagon not to factor into its selection criteria alleged subsidies that Airbus was receiving from European governments, even thought the U.S. had sued the European Union at the World Trade Organization over subsidies provided to Airbus.

This allowed the Airbus plane to best Boeing by offering a lower price, according to Boeing’s supporters.

The Air Force’s decision could affect Boeing jobs in Washington, Illinois and Kansas, a Republican stronghold. Members of Congress from those states have lambasted the Air Force, but others support the deal for parochial reasons. Northrop Grumman will build parts of its tankers in the U.S., and they say their winning bid could add at least 2,000 jobs in Alabama and support 25,000 jobs nationwide.

Lieberman disputes the McCain criticisms even though he opposes the Air Force’s decision.

Connecticut is on the losing end of the deal, since Pratt Whitney, a Connecticut firm that builds engines for Boeing, stood to gain from a victory by the Chicago-based company.  

“I am very disappointed by the decision the Air Force has made, but to blame it on Sen. McCain is the ultimate of political silliness,” Lieberman told The Hill.

Keith Ashdown, with the nonpartisan watchdog Taxpayers for Common Sense, said that the Democrats who have campaigned on an anti-corruption platform and pushed for strong oversight over industry contracts in Iraq and Afghanistan are walking a fine line with their criticism of McCain.

“You can’t have your convenient corporate crook,” said Ashdown.  “You have to look at everybody through the same lens,” including Boeing.

The only one to blame for the current situation is Boeing, Ashdown added. “This was theirs from day one,” he said, stressing that Boeing broke the law. “This idea that any lawmaker is to blame is a joke.”

Sen. John Warner (R-Va.), who was the chairman of the Senate Armed Services Committee at the time McCain took on the Air Force’s lease deal with Boeing, said that McCain did the right thing in pushing for competition in the tanker contract.

“I backed McCain 100 percent on that,” said Warner, who added that since he was the committee’s chairman at the time, “if they want to put [anyone in] the gallows, put my neck in it.”

That hasn’t stopped Democrats from trying to capitalize on an opportunity to attack McCain and play tough on his signature issue of national security. They argue that by awarding the contract to a consortium that includes Airbus, the Air Force is endangering the U.S. defense industrial base.

“We will not have the industrial and technological base necessary to ensure our national security because it will fade, it will diminish, it is not strengthened,” House Speaker Nancy Pelosi (D-Calif.) told reporters this week.

While Pelosi refrained from blaming McCain, she said that because McCain intervened in the Air Force’s dealings, “we have a situation … where this work may be outsourced.”

Others have been more direct. Rep. Norm Dicks (D-Wash.) a staunch Boeing supporter, told constituents in his district earlier this week, "I hope the voters of this state remember what John McCain has done to them and their jobs."

The Air Force is expected to debrief Boeing on the contract decision on Friday and Northrop Grumman next week. Boeing has 10 days after the debriefing to decide whether it would formally protest the contract award with the Government Accountability Office. The GAO has 100 days to either uphold or deny the protest.