On the same program, Wisniewski said his goal was not to hurt Christie's prospects but to get at the truth of what happened.
"New Jersey politics is rough and tumble; that isn't going to change," Wisniewski said. "But abusing power should not be condoned."
Christie's press office distributed Giuliani's comments by e-mail, and three GOP members of the Assembly echoed him, calling on Wisniewski, a former chairman of the state Democratic Party, to step down from the investigation.
The governor has strong ties to Giuliani; many of his top political advisers once worked for the mayor.
Christie, in his capacity as chairman of the Republican Governors Association, arrived in Florida on Saturday to headline three fund-raisers for Florida Gov. Rick Scott, who faces a tough reelection campaign in this perennial swing state.
It was Christie's first out-of-state political trip since Jan. 9, when he apologized for four September days of jammed traffic in Fort Lee and announced that he had fired the aide involved in the closure of the access lanes, apparently as retaliation against the city's Democratic mayor for declining to endorse Christie's reelection.
Before Christie left town, Wisniewski's committee issued 20 subpoenas, including some to members of the governor's inner circle. On Saturday, Hoboken Mayor Dawn Zimmer accused Christie of threatening to withhold Hurricane Sandy relief aid because she opposed the project of a politically connected developer. On Sunday, Zimmer met with the U.S. attorney.
Sunday afternoon, as the AFC championship game was getting underway, Christie met with major party donors at the home of Ken Langone, the billionaire cofounder of Home Depot. It was not a fund-raiser, but an intimate chance for the donors to chat informally with Christie, Langone said beforehand.
Langone led a group of establishment Republicans who urged Christie to make a late entry into the 2012 presidential campaign. Many in the GOP donor class already had begun coalescing around Christie as an electable alternative to the party's far right who could lead them back to the White House in 2016. They cite Christie's landslide reelection in November, in which exit polls showed he won a majority of the votes of women and Hispanics.
"I think he's amazing," said one attendee at Langone's home, who declined to give his name. "I believe he's going to be the solution for tomorrow for us [Republicans] and solve all our problems."
The man was interviewed as he waited for the light to change at the entrance to Lost Tree Village, the golf development where Langone lives. He said Christie had brought up the bridge affair, adding, "He just talked about accountability."
After the gathering, Christie attended a larger Republican Governors Association fund-raiser at the golf clubhouse. Miami GOP strategist Ana Navarro, who was there, quoted Christie as saying, "I have not enjoyed the last 11 days. No sane person would. I am being tested." Navarro tweeted those remarks and expanded on them to the Tampa Bay Times, quoting Christie as saying, "I will be fine. We all face challenges in life, and you just have to deal with them. I will keep swinging and do what is right for the people of my state."
Sid Dinerstein, former chairman of the Palm Beach County GOP, said he had heard from many donors who are taking a "wait and see" approach on Christie for now but added that conservatives were not going to get behind him. "He did more than any single person to reelect Barack Obama" by embracing the president after Hurricane Sandy and has advanced himself by bashing fellow Republicans, Dinerstein said.
"The Democrats are attacking because they believe Chris Christie could be president," said Dinerstein, who was not at the Christie events. "Republicans know that he could be the nominee but would never be elected president because 10 million Republican voters would stay home."