It’s been 48 years, but the similarities between John F. Kennedy’s election, transition and inauguration and Barack Obama’s are striking: a new president in his 40s, a product of Congress, eloquent and elegant, and taking office in a world of trouble.

Despite of those similarities and others — notably, Obama making history as the first African-American president, Kennedy, as the first Roman Catholic — Obama’s team did not reach out for transition advice to Kennedy’s top aide, Ted Sorensen.

Nor did President George W. Bush’s outgoing chief of staff, Josh Bolten, invite Sorensen to a White House gathering of 13 past chiefs of staff on Dec. 5 to give advice to incoming chief Rahm Emanuel.

In an interview, Sorensen took the exclusions in good humor, jesting with an apt quote from Kennedy’s inaugural address, which he helped write. “The torch has been passed to a new generation.”

Nonetheless, he offered some comparisons and counsel — one of which Obama, by instinct, actually has adopted on his own.

In 1960, taking advice from the late presidential scholar Richard Neustadt, Sorensen said that as one of his first acts as president-elect, Kennedy announced he was retaining in office J. Edgar Hoover as FBI director and Allen Dulles as CIA director — a mistake.

“May he rest in peace, [Neustadt] was the one who thought there should not be a turnover when parties change, as a question of good government, at the head of the FBI and the CIA,” Sorensen said.

Hoover’s long and abusive tenure caused Congress to give the FBI director a 10-year term, so Obama could not replace incumbent Robert Mueller if he wanted to, but he did put in his own nominee, former White House Chief of Staff Leon Panetta, at the CIA.

Sorensen, now an 80-year-old New York attorney, was just 32 when Kennedy named him as his top aide within days of his 1960 election victory.

He had a title, “special counsel to the president,” borrowed from the Roosevelt and Truman administrations — which is why, Bolten said, he was not included at the Dec. 5 chiefs-of-staff gathering.

Unlike almost every other president since Lyndon Johnson, Kennedy wanted no chief of staff, reacting against the military pattern of his predecessor, Dwight Eisenhower.

“Kennedy would not have been comfortable with somebody else deciding who his visitors were and which pieces of paper reached his desk,” Sorensen said. “I think our system worked pretty well” — a “spokes of a wheel” system in which several top aides had direct access to the president.

The youthful Sorensen, though, was Kennedy’s closest aide — responsible for organizing the transition, connecting with Cabinet appointees (“it’s amazing how people suddenly returned my calls,” he recalled) and later serving as chief of domestic policy, chief speechwriter and confidant on everything from politics to foreign policy.

And all with at first, three aides and then two. A huge difference between Kennedy and Obama is the size of their White House staffs. “I had a picture on my wall of the Kennedy White House professional team,” he said, “and we’re all standing on the steps of the West Wing. With Clinton and Bush, you’d need a stadium.”

Sorensen is skeptical of Obama’s penchant for hiring White House “czars” to co-ordinate various aspects of policy. “I’m concerned that a large, diverse and very talented team may have more than one strong voice.

“If you have too many people who can pick up the phone and say, ‘This is the White House calling,’ it leads to trouble,” Sorensen said.

But turning back to similarities, Sorensen said that Kennedy, like Obama, started planning early for the transition.

Soon after his nomination in July 1960, Kennedy quietly contacted Neustadt, then a professor at Columbia University and author

of the landmark book, “Presidential Power and the Modern Presidents,” and Harry Truman’s former top aide, Clark Clifford, to separately prepare organizing memos for his administration.

He told the two not to contact each other, but Sorensen said they rendered remarkably compatible advice. Neustadt’s 12 memos, the first dated Sept. 15, still make for enlightening reading and Obama, regardless of whether he has read them, seems to be following the professor’s advice.

“Nothing would help the new administration more than [creating] a first impression of energy, direction, action and accomplishment,” Neustadt wrote — but he recommended not following Franklin Roosevelt’s example of getting Congress to pass a huge agenda in 100 days.

“As [Kennedy] said in his inaugural address, ‘All this will not be accomplished in 100 days,’ and we didn’t like to be judged on that measuring stick,” Sorensen said. “And, the circumstances were so different from FDR, who took office by a landslide in the middle of a depression. Kennedy had taken office with a popular margin then the smallest of the 20th century and the so-called Dixiecrat-Republican majority in Congress was against him.”

Obama is arriving in a situation more like FDR’s than Kennedy’s, whose early crises were foreign — notably, the Bay of Pigs disaster in April 1961 — not domestic. Obama first called for an economic rescue bill to be passed by Inauguration Day. Now the deadline is Feb. 13 and may slip.

One other difference between 1960-61 and the present is that, in Kennedy’s day, the government provided no transition offices, funding or legal structure. “We had to make it up as we went,” Sorensen recalled.

Kennedy’s transition headquarters sometimes was his home in Georgetown and sometimes his family’s compound in Palm Beach, Fla., or the Carlyle Hotel in New York.

Kennedy was rich enough to afford to support his part of the effort, but volunteers — including members of the transition task forces Sorensen assembled — paid expenses out of their own pockets.

In both cases, the transition process has worked rather smoothly. Obama apparently will lose just one Cabinet nominee during the confirmation process. Kennedy lost none. Obama’s transition has been virtually leak-free. So was Kennedy’s — “because we had no factions.”

Sorensen does not regard it as a handicap that Kennedy and Obama are products of Congress and have no executive experience. “The key quality is the president’s judgment. Kennedy had it,” he said.

But one area where Kennedy fell down, Sorensen acknowledges, was in relying too much on the advice of “experts” — in the military and the CIA — who planned and sold him on the Bay of Pigs invasion of Cuba, a military disaster and political fiasco.

“That served as the bookend that ended our transition,” he said. “After that, we all knew we had to ask tough questions.” Sorensen is convinced, for instance, that prudence would have kept Kennedy from even committing large numbers of combat troops to Vietnam. “He was repeatedly urged to do it and he repeatedly refused,” Sorensen said.

Today, one can expect from Obama an inaugural address rivaling Kennedy’s in eloquence and vision. Participants, though, will be hoping for one difference between today and Jan. 20, 1961: no city-choking, no blizzard and a temperature above 24 degrees.