But his confrontations are not always that public.

In 2011, Mr. Christie held a news conference where he accused State Senator Richard J. Codey of being “combative and difficult” in blocking two nominees. Mr. Codey, a Democrat who had served as governor following the resignation of James E. McGreevey, responded that he had not only signed off on the nominations, but had held a meeting to try to hurry them along.

Three days later, Mr. Codey was walking out of an event in Newark when he got a call from the state police superintendent informing him that he would no longer be afforded the trooper who accompanied him to occasional public events — a courtesy granted all former governors. That same day, his cousin, who had been appointed by Mr. McGreevey to the Port Authority of New York and New Jersey, was fired, as was a close friend and former deputy chief of staff who was then working in the state Office of Consumer Affairs.

“I understand politics, that a new administration comes in,” Mr. Codey said, but he believed this was not about Mr. Christie bringing in his own people. “This was all about sending a message.”

The governor laughed at the allegation of retribution, and his spokesman belittled the Democratic Party chairman who complained about it.

Later that year, the governor was pressing hard on Alan Rosenthal, the Rutgers political scientist whom Republicans and Democrats had chosen as the tiebreaking member of the commission that was redistricting the state’s legislative districts. Mr. Christie wanted Mr. Rosenthal to vote for the map put forward by the Republicans on the commission, but instead he chose the Democrats’ plan, saying it offered more stability.

Soon after, Mr. Christie used his line-item veto to cut $169,000 for two programs at Mr. Rosenthal’s institute at Rutgers.

The apparent payback is not always directed at Democrats — Mr. Christie can be just as hard on Republicans in an attempt to enforce party discipline.