It was a simple gesture, a gift from one man to another, but the tiny brass object former Lynn Mayor Thomas P. Costin Jr. handed Vice President Joseph R. Biden Jr. on Oct. 29 left the vice president grateful and humbled.Biden headlined a rally at the Lynn YMCA a week before Seth Moulton’s election to Congress and greeted Costin, who surprised Biden by handing him a tie clip that the late John F. Kennedy gave Costin in 1958.”I said, ?Mr. Vice President, I want you to know I have only one of these left. What I’m giving you came from Jack Kennedy’s hands to my hands to your hands,'” Costin said.Biden didn’t want to accept a gift that clearly held a great deal of sentimental value for Costin.”Mr. Vice President,” Costin told him, “Jack Kennedy would want you to have it and I want you to have it.”Biden accepted the gift, but insisted on repaying the favor, inviting Costin, his wife, Noel, and their grandson, James Hooper, to visit him at the White House. “My wife wants to wait until the cherry blossoms bloom,” Costin said.The encounter at the YMCA was not the first time Costin and Biden met. In 2004 when the Democratic National Convention was in Boston, Biden was outside the TD Garden (then the FleetCenter) waiting for a ride when Costin came upon him.”We spent a long time talking about politics and helping people and what the Democratic party meant,” Costin said. When they saw each other at the YMCA, Biden immediately remembered that meeting, Costin said.Costin’s gift to Biden was a chance for a Lynn native with a life steeped in politics to proclaim his allegiance to JFK dating back to Costin’s youth.The pair first met in 1946 when Costin was a 19-year-old fresh out of the Marine Corps and starting his political career with a run for the Ward 7 City Council seat. (His Marine recruiter had been Sgt. Edward Cahill, who would later serve with Costin on the City Council and became a highly respected sports editor at The Item.) Costin shook hands with congressional candidate John F. Kennedy after happening upon a political rally in the North End.After JFK survived an 11-candidate free-for-all in the Democratic primary and cruised to an easy victory in the general election, Costin sent him a hand-written note of congratulations. A year later when Costin was elected to the City Council as a 21-year-old – the youngest councilor ever elected to that point – JFK returned the favor.The two men subsequently met on several occasions, and Costin became a loyal supporter and confidante of Kennedy, hosting a house party at his Pennybrook Road home in January 1952 when JFK was mounting a successful run for U.S. Senate. Kennedy stayed until after midnight and was the last to leave.When Kennedy ran for re-election in 1958, his brother, Edward M. Kennedy, led the campaign and Costin was asked to fill an important role. JFK had just announced at a Boston hotel rally that Costin would lead the voter registration drive in Massachusetts when he turned to Costin and handed him six tie clips cast to resemble the PT-109, the World War II vessel Kennedy commanded. Each clip bore the candidate’s last name.”Hand these out where they will do the most good,” Costin recalled Kennedy telling him. JFK won the election by a nearly 3-1 margin, the largest majority in Massachusetts history.Costin, 88, was a delegate for presidential candidate Kennedy at the Democratic National Convention in Los Angeles in 1960, four months before JFK was elected 35th president of the United States. Kennedy appointed Costin Postmaster in Lynn in 1961, a post Costin held for more than 30 years.While Costin’s friendship with Kennedy was severed by tragedy in 1963 when the president was assassinated, Costin held onto the mementoes that signified happier times. He had given away four of the tie clips and kept two for himself.Now, he is down to one, but thrilled the other is in the hands of the vice president of the United States.