After a top New Jersey official at the Port Authority, David Wildstein, ordered the lane closings at the George Washington Bridge that clogged Fort Lee, N.J., for four days in September, the authority’s New York-appointed executive director, Patrick J. Foye, exploded with anger and ordered the lanes reopened. But then the authority’s New Jersey-appointed chairman, David Samson, expressed outrage over Mr. Foye’s outrage, accusing him of leaking the story of the lane closings.

The Port Authority of New York and New Jersey is a bistate agency that was designed to take politics out of the operation of the region’s trade and transportation infrastructure. But as portrayed in email traffic released this week by investigators of the lane-closing scandal, it appears consumed by politics: a split personality beholden to the whims of the two rival governors who control it.

“It’s like there’s a Berlin Wall down the middle of the halls in there,” said David J. Gallagher, the president of the Port Authority Retirees Association. “On the one side, it’s New Jersey people working; on the other side, it’s New York people working. A divided management just does not work.”

The agency, created in 1921, operates a network of airports, bridges, tunnels, cargo terminals and real estate, including the World Trade Center — assets once seen as too important for politicians to be fighting over. That long ago proved to be a pipe dream. But the cross-Hudson competition, patronage and political intrigue appear to have reached new heights, as Gov. Chris Christie, a Republican, faces a growing scandal over Mr. Wildstein’s decision to order the lane closings as an act of political retaliation.