Mr. Giuliani has “obviously evolved, and in some ways not for the better,” says Andrew Kirtzman, author of “Rudy Giuliani: Emperor of the City.” “Once he cast his lot with Trump, he went all the way, which is how Rudy Giuliani does things.”

For some who remember the old Mr. Giuliani, the New York mayor who personified bipartisan leadership after Sept. 11, 2001 – earning him an honorary knighthood from Queen Elizabeth II – it’s been a stark transformation. In some ways, it mirrors that of American politics writ large, as the post-9/11 high point of unity and resolve dissipated into increasingly bitter partisanship during the Bush and Obama presidencies and the tabloid ugliness of the Trump era.

Lately, Mr. Giuliani has come under increasing scrutiny for his involvement in what effectively became a shadow foreign policy. His efforts to get Ukraine to investigate former Vice President Joe Biden and his son in an alleged quid pro quo for military aid sit at the heart of the House impeachment inquiry into the president.

Over the long arc of his career, Rudy Giuliani has gone from Democrat to moderate Republican to Trump Republican; from mob-busting federal prosecutor to celebrity mayor to controversial personal lawyer for President Donald Trump.

Peter King didn’t have much use for Rudy Giuliani when they first met in the summer of 1967.

Both were 23-year-old interns at the Wall Street law firm of future President Richard Nixon. Another partner at the firm, future Attorney General John Mitchell, assigned them to work together on a municipal bonds project.

The two law students, though both graduates of Roman Catholic high schools in Brooklyn, didn’t see eye to eye on much. Mr. Giuliani was “pretty liberal” – a Bobby Kennedy supporter – says Mr. King, who was and is a Republican, currently in his 14th term in Congress. Mr. Giuliani rooted for the Yankees, Mr. King for the Mets.

They also had contrasting styles. “He thought I was very caustic or opinionated when I was writing; he was being more judicious,” Congressman King tells the Monitor. “Rudy’s very smart. He was much more into the law than I was.”

Decades later, the 9/11 attacks brought the two New York pols together, and they have been friends ever since. But over time, one has gone through a profound evolution. After those early days as a Democrat, Mr. Giuliani went from political independent to moderate Republican – so moderate he endorsed Democrat Mario Cuomo for governor in 1994 – to Trump Republican, and from mob-busting federal prosecutor to celebrity mayor to controversial personal lawyer for President Donald Trump. Still, longtime friends see “the same old Rudy,” a bit grayer but with the same no-holds-barred approach to life.

“Certainly everything he’s done from the time he became U.S. attorney has been either Page One or Page Six,” says Mr. King, referring to the New York Post’s gossip page. Mr. Giuliani’s third divorce, from wife Judith, has provided recent fodder.

Mr. King retains a strong bond with Mr. Giuliani – but the same cannot be said for some of the ex-mayor’s former aides, several of whom have been publicly critical of Mr. Giuliani’s work for Mr. Trump in what effectively became a shadow foreign policy. Mr. Giuliani’s efforts to get Ukraine to investigate former Vice President Joe Biden and his son in an alleged quid pro quo for military aid sit at the heart of the House impeachment inquiry into the president.

Carolyn Kaste/AP/File Then-President-elect Donald Trump (right) and former New York Mayor Rudy Giuliani pose for photographs outside the clubhouse at the Trump National Golf Club Bedminster in Bedminster, New Jersey, Nov. 20, 2016.

“‘America’s Mayor,’ as Rudy was called after Sept. 11, is today President Trump’s bumbling personal lawyer and henchman, his apologist and defender of the indefensible,” wrote Ken Frydman, Mr. Giuliani’s 1993 campaign press secretary, in a New York Times op-ed.

Mr. Giuliani “lost his way” after he became a lobbyist and insider, former political adviser Rick Wilson recently told Politico.

Top aides to Mr. Trump have also expressed reservations about the president’s lawyer. “Giuliani’s a hand grenade who’s going to blow everybody up,” former national security adviser John Bolton was recently quoted as saying.

In the latest blow to Mr. Giuliani’s credibility, the same U.S. attorney’s office in Manhattan that he once ran is now investigating him over his ties to two Soviet-born men arrested on campaign finance charges. The Justice Department, where he was once the No. 3 official, put out an unusual statement distancing itself from Mr. Giuliani. The former mayor has rebuffed congressional demands for documents.

While speaking to reporters Friday from the White House south lawn, Mr. Trump defended his friend. “He was the greatest mayor in the history of New York, and he’s been one of the greatest crime-fighters and corruption fighters,” Mr. Trump said. “Rudy Giuliani is a good man.”

A transformation that mirrors U.S. politics

For some who remember the old Mr. Giuliani, the mayor who personified leadership on and immediately after Sept. 11, 2001 – earning him an honorary knighthood from Queen Elizabeth II – it’s been a stark transformation.

After the 9/11 attacks, Mr. Giuliani seemed to be everywhere – comforting grieving families, standing in on at least one occasion for the slain father of the bride at a wedding.

“He showed a humanness that he hadn’t exhibited in the past,” says Doug Muzzio, a political scientist at Baruch College in New York City.

In a way, the transformation of Mr. Giuliani from that post-9/11 period to today mirrors that of American politics writ large. The nation has gone from a high point of unity and resolve to increasingly bitter partisanship during the Bush and Obama presidencies to the tabloid ugliness of the Trump era.

Mr. Giuliani has “obviously evolved, and in some ways not for the better,” says Andrew Kirtzman, who covered the mayor as a local TV reporter and wrote a biography, “Rudy Giuliani: Emperor of the City.”

“Giuliani was always a bombastic public figure, but as mayor, he used that bombast for tactical reasons,” Mr. Kirtzman says. His example: Mr. Giuliani’s “terrorizing” of the public schools chancellor until he resigned, so the mayor could take control of the school system.

Mr. Giuliani’s Achilles’ heel was race relations, but he is widely credited with cleaning up Times Square, bringing down crime, and fighting corruption.

“He was hardly an unguided missile,” Mr. Kirtzman says. “He was a very, very, very smart strategist, with a very tempestuous way of getting things done. I don’t see that this time around. I see less discipline in how he’s proceeding.”

Getting at the “why” behind Mr. Giuliani’s transformation is tricky, but there are theories. Some observers point to Mr. Giuliani’s failed 2008 presidential campaign as a pivotal event. He wasn’t one to go off and write books. He wanted to stay in the game.

Advocating for Mr. Trump, it seems, was his ticket back to political relevance. And he plunged into it with gusto, if at times in embarrassing fashion. In one of his more memorable recent TV appearances, with CNN’s Chris Cuomo, Mr. Giuliani at first denied that he had asked Ukraine to investigate the Bidens, then 30 seconds later stated he had. The past two weeks, he has been notably absent from TV.

Tale of two New Yorkers

The similarities between Messrs. Trump and Giuliani are obvious: both native New Yorkers, limelight seekers, increasingly conservative over time, thrice married. But they weren’t always allies or even friendly. In 1986, when Mr. Giuliani was a prosecutor and Mr. Trump was coming up in real estate, the two were on opposing sides of a corruption trial involving a Trump-connected public official.

They didn’t become confidants until Mr. Trump began his march to the presidency, Giuliani observers say.

Still, the two had traveled in the same circles for years. They attended each other’s third weddings. Mr. Trump donated to Mr. Giuliani’s aborted Senate campaign in 1999. The mayor spoke at the funeral of Mr. Trump’s father.

Perhaps their most memorable interaction – especially now, in hindsight – came in a video produced for a charity dinner in 2000. Mr. Giuliani is in drag, and Mr. Trump is himself, behaving in an aggressively flirtatious way.

“Oh, you dirty boy, you!” scolds Mr. Giuliani as “Rudia,” before slapping Mr. Trump.

“You can’t say I didn’t try,” the future president shrugs.

Years later, a month before the 2016 election, Mr. Giuliani would emerge as the GOP nominee’s most aggressive defender after an old “Access Hollywood” video leaked of Mr. Trump bragging in vulgar terms about sexually assaulting women.

Mr. Giuliani has been defending him ever since, and in April 2018 was named to Mr. Trump’s personal legal team – unpaid, it turns out. Not that Mr. Giuliani isn’t interested in money. When his time as mayor ended, soon after 9/11, he went into business, marketing his services as a management and security consultant and commanding high speaking fees.

Public documents from his latest, ongoing divorce show the former mayor is worth many millions of dollars, with assets that include six homes.

“That’s the funny thing about these New York folks,” says Lee Miringoff, director of the Marist College poll in Poughkeepsie, New York. “If you take Hillary [Clinton], Giuliani, Trump – what’s prominent for all of them was the idea that there was money to be made.”

Mr. Giuliani, who comes from working-class roots, didn’t always pursue the high life. As a prosecutor, “there was something very spartan about him,” says Mr. Kirtzman, the biographer. “He was never seen out at parties or nightclubs. In many ways, he was a scold back then.”

Mr. King, the congressman, also remembers Mr. Giuliani during their summer law internship as not all that gregarious. Now, when Mr. King’s family is in Washington, they head over to the Trump hotel for drinks, and there’s Mr. Giuliani. On one occasion, “he comes over, and he’s telling my grandson how great I am,” says the congressman.

Mr. King says he isn’t all that surprised by Mr. Giuliani’s behavior today. “He’s playing a different role – the role of getting attention, and trying to get attention away from the Democrats.”

The congressman describes Mr. Giuliani – until recently, at least – as more of a TV advocate. “Rudy’s thing is, always be on offense,” Mr. King says. “He and President Trump are almost identical in that. Never back off, just keep going. No matter what they throw at you, you throw twice as much back.”

And what of the Giuliani-Nixon connection back in 1967? It is a point of historical coincidence that’s almost uncanny, given current events. (In 1974, President Nixon was heading toward impeachment when he resigned.)

“We did have lunch with Nixon one day,” Mr. King says. “In fact, I saved the seating chart. All of us sat around the table. Richard Nixon was at the head, John Mitchell was at the other end.”

Mr. Nixon sat with the summer interns for about two hours, going around the table and asking questions, Mr. King recalls.

Get the Monitor Stories you care about delivered to your inbox. By signing up, you agree to our Privacy Policy

Heading home on the train that night – Mr. King and Mr. Giuliani also lived near each other – the two argued about the session with Mr. Nixon “in a friendly way,” Mr. King says. At the end of the summer, after Mr. King returned to law school, Mr. Giuliani (who stayed on a little longer) sent him a letter on the Nixon firm’s stationery.

“He said I had done a good job and he missed my brilliance,” Mr. King says. “I still have that letter somewhere.”