(CNN) There are people in Washington who would be happy to see Joe Lieberman return to public life. They just don't happen to be members of the party that once nominated him for the second highest office in the land.

That's what happens when you commit partisan treason.

Lieberman, a longtime Democratic senator, became a pariah in his own party in 2008 when he not only endorsed the presidential bid of his GOP buddy, John McCain, but lambasted his own party's nominee, Barack Obama, during a speech at the Republican Convention.

Now, it's Republicans, rather than Democrats, who are welcoming the news that President Donald Trump might nominate Lieberman to head the FBI. And it is Republican senators, and possibly a smattering of Democrats, who would most likely vote to confirm him.

"Joe Lieberman is probably the only person that could get 100 votes in the Senate," Sen. John Cornyn, a Texas Republican who earlier this week took himself out of the running to be FBI director, tweeted Thursday in the kind of overstatement common in the capital these days.

Sen. Lindsey Graham, a South Carolina Republican and one of Lieberman's closest Senate friends, called him a "pillar of credibility."

But not all Democrats all see it that way.

"I don't think many Democrats in the Senate are going to take it very well," said veteran strategist Jim Manley.

A Senate Democratic leadership aide told CNN "the overwhelming majority" of Senate Democrats would vote against Lieberman.

Sen. Dianne Feinstein, the top Democrat on the Judiciary Committee, said Trump should pick someone from law enforcement.

"I think that the political part of this is not the best part for the FBI," Feinstein said on CNN's "The Situation Room." "The FBI has to have someone that every member of that agency respect because they know their law enforcement, they know they're not going to cave to political whims, and they know that they're talented in doing the law enforcement job."

Perhaps it's not surprising that Trump, a nascent politician who never has adhered to party orthodoxy, would be drawn to Lieberman, a long-time officeholder who didn't either.

Like Trump, Lieberman never fit squarely into a box. And like Trump, Lieberman always did what he saw fit, critics be damned.

In 1968, Lieberman ran the Connecticut presidential campaign of liberal Democrat Robert F. Kennedy. Twenty years later, he ran for the Senate. And for much of his two dozen years there, he was a centrist who, like Bill Clinton, tried to offer an alternative to the liberal vision that long dominated the Democratic Party.

But Lieberman saw himself as a moralist. An Orthodox Jew who often invoked his religious upbringing, Lieberman took to the Senate floor in September 1998 to chastise Clinton for engaging in an extramarital affair with a White House intern, Monica Lewinsky. While he stopped short of calling for Clinton's impeachment, Lieberman branded the President's behavior "immoral" and "disgraceful" in a speech that many of his colleagues viewed as unnecessarily sanctimonious.

It turns out that upbraiding the President of his own party didn't hurt Lieberman. In fact, his star rose.

In 2000, Clinton's vice president and would-be successor, Al Gore, chose Lieberman as his running mate, making him the first Jew on a major-party ticket. Gore won the popular vote, but not the Electoral College. Some even blamed Lieberman after he botched part of the recount in an election so close it ultimately was decided by the Supreme Court.

Iraq war and the "Three Amigos"

Once again, Lieberman went on to live another life back in the Senate. But he edged farther away from the center of his party. After the terrorist attacks of September 11, 2001, Lieberman supported President George W. Bush's plans to create the Department of Homeland Security. He also was one of the Democrats' staunchest supporters of the Iraq War.

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In 2004, Lieberman launched his own presidential campaign, but by then the war was unpopular and, apparently, so was he -- particularly within his own party. When he ran for reelection to the Senate two years later, Lieberman lost in the Democratic primary. That's when he became an independent, a strategic move that allowed him to win back his seat.

This time, when he returned to Washington, Lieberman no longer fit in. He caucused with Democrats, but was something of an outsider.

It was during the post-9/11 years that Lieberman linked arms with Republicans Graham and McCain, two other hawks who, like their Democratic friend, were known to thwart their party. The trio traveled the world together and became known as the "Three Amigos." So high was their mutual regard that McCain reportedly wanted Lieberman to be his 2008 running mate, though he eventually succumbed to pressure to pick conservative Sarah Palin instead.

Still, Lieberman stood by his friend.

"In the Senate, during the three-and-a-half years that Sen. Barack Obama has been a member, he has not reached across party lines to ... accomplish anything significant, nor has he been willing to take on powerful interest groups in the Democratic Party to get something done," he said at the 2008 Republican convention.

Democrats viewed that speech as blasphemy.

"He could have given a speech defending John McCain, but instead he went on the offense and blistered Obama over his lack of foreign policy skills, which were a major Republican talking point," said Manley, a long-time senior aide to Harry Reid, the former Democratic Senate leader. "It caused a lot of ill will."

After the election, Democratic senators pressured Reid to kick Lieberman out of the caucus and prevent him from chairing the homeland security committee. Reid resisted, however, saying it was better to keep Lieberman in the fold.

And now, Lieberman might start another new life in Washington, courtesy of a Democrat-turned-Republican, a president who also has charted his own path.

This time, however, the senator who so often crossed party lines would have an entirely different role. He would be part of no party.

This time, he truly would be on his own.