When people call the late Sen. Frank R. Lautenberg a “fighter,” they aren’t just talking about his celebrated successes as a policymaker.

In fact, the New Jersey Democrat engaged in some notoriously nasty political skirmishes — with members of both parties — over the years.

“It’s no mystery that Sen. Lautenberg and I didn’t always agree,” New Jersey Gov. Chris Christie said.

“I think the best way to describe Frank Lautenberg in the way he would probably want to be described to all of you today is as a fighter,” Christie, a Republican, said of the longtime Democratic senator who died before dawn Monday at age 89. “Sen. Lautenberg fought for the things he believed in, and sometimes he just fought because he liked to.”

But Christie, who under New Jersey law gets to appoint a successor, was perhaps a minor foe compared to some of the battles Lautenberg had with fellow Democrats.

There was New Jersey Democratic Sen. Robert G. Torricelli. Lautenberg retired in 2001, but he ended up succeeding Torricelli after he decided abruptly not to seek re-election in 2002, after being admonished by the Ethics Committee. Democrats, scrambling for a candidate, turned to Lautenberg for the 34-day campaign.

A trip through the Roll Call archives serves as a reminder that when Torricelli and Lautenberg co-existed, it often wasn’t pretty. Here’s just one example: In 1999, shortly after Lautenberg’s first retirement announcement, the two senators feuded at a Democratic caucus meeting over comments that Torricelli made favorable to New Jersey’s governor at the time, Republican Christine Todd Whitman.

The sharp exchange started while Torricelli was briefing roughly two dozen Senate Democrats about the 33 Senate races this cycle. He was suddenly interrupted by Sen. Edward Kennedy (D-Mass.), who wanted to know why Torricelli had not touched on New Jersey.

At that point, Lautenberg stood up to claim Torricelli was jeopardizing Democratic chances to hold onto the New Jersey seat. Torricelli challenged Lautenberg to back up his charge, so Lautenberg pulled out an article from The Bergen (County, N.J.) Record that appeared the day after he announced his retirement.

“I actually have a closer personal relationship with Governor Whitman,” Torricelli told the newspaper. He added that Lautenberg’s announcement was “part of a generational change in the Democratic Party” of New Jersey.

When Torricelli attempted to brush off Lautenberg’s request, sources said several other Democrats, including Sens. Paul Wellstone (Minn.) and Jay Rockefeller (W.Va.), insisted that Torricelli give them a more thorough explanation of what he said about Whitman.

Torricelli countered that he was working hard as DSCC chairman to help Democrats recapture the Senate, pointing out that he had just flown in from California that morning, and he insisted that his political acumen was as sharp as that of anyone in the Democratic Caucus.

Several sources said Torricelli, infuriated by Lautenberg’s attack on him, refused to let the matter end. Upon completing his presentation, Torricelli rushed over to Lautenberg and “vowed to get even with him,” according to one source who heard the exchange.

Torricelli then swore at Lautenberg, according to Senators and staffers who witnessed the argument. Torricelli also vowed to Lautenberg, “I’m going to cut your (genitals) off.”

Several Democratic Senators who were present throughout the exchange, admitting pro-Lautenberg sympathies, suggested Torricelli could have avoided the latest incident by just giving Lautenberg his due and admitting that he may have been too favorable to Whitman in his comments.

“Frank Lautenberg has been around here for a long time and fought a lot of tough battles,” said one Democratic Senator, insisting on anonymity. “That counts for a lot.”

Another Democratic Senator said Torricelli “was out of line” for making any public statement that helped Whitman.

filed papers to seek the Senate seat

Lautenberg also drew a Democratic primary challenger in 2008, when he trounced Rep. Robert E. Andrews, picking up 59 percent of the vote along the way. Andrews then returned to the House.