Sen. Edward "Ted" Kennedy (D-Mass) died late Tuesday night at his home in Hyannis Port, Mass. He was 77.
"We've lost the irreplaceable center of our family and joyous light in our lives," the Kennedy family reported in a statement, "but the inspiration of his faith, optimism, and perseverance will live on in our hearts forever."
In office from November 1962 until his death, Kennedy served nine terms in the Senate, making him the third-longest-serving senator in U.S. history. At the time of his death, he was the second most senior member of the Senate.
"His ideas and ideals are stamped on scores of laws and reflected in millions of lives - in seniors who know new dignity, in families that know new opportunity, in children who know education's promise, and in all who can pursue their dream in an America that is more equal and more just - including myself," commented President Obama the day after Kennedy's death.
The Human Rights Campaign – the nation's largest lesbian, gay, bisexual and transgender (LGBT) civil rights organization – meanwhile hailed Kennedy as an "unwavering supporter of the LGBT community."
"The nation has lost its greatest champion and strongest voice for justice, fairness, and compassion," said HRC President Joe Solmonese. "The loss to our community is immeasurable. There was no greater hero for advocates of LGBT equality than Senator Ted Kennedy. From the early days of the AIDS epidemic, to our current struggle for marriage equality he has been our protector, our leader, our friend. He has been the core of the unfinished quest for civil rights in this country and there is now a very painful void. Our hearts go out to the Kennedy family."
Since news broke of Kennedy's cancerous brain tumor last year, the Democratic senator has been battling his illness and, in the last several months of his life, kept largely out of sight. The last time he cast a vote was reportedly in April.
In Kennedy's absence, Sen. Chris Dodd (D-Conn.) had taken over his role on the Health, Education, Labor and Pensions Committee, but Republican senators and other observers said that the lack of Kennedy's physical presence had resulted in less consultation with them and was making successful negotiation more difficult.
"While some will remember Kennedy as a 'liberal icon,' he also brought bipartisanship and civility to the political debate," explained U.S. Chamber of Commerce President and CEO Thomas J. Donohue in a statement.
"His mastery of the issues complimented an ability to reach across the aisle and consider all sides of an issue," he added.
Sen. Judd Gregg (R-N.H.) told The Associated Press that if Kennedy had been physically up to it and been engaged on the current struggle over health care reform, "we probably would have an agreement by now."
In his comments Wednesday, the president also acknowledged Kennedy's ability to "passionately battle others and do so peerlessly on the Senate floor for the causes that he held dear, and yet still maintain warm friendships across party lines."
"[I]n the United States Senate, I can think of no one who engendered greater respect or affection from members of both sides of the aisle," said Obama, adding that Kennedy's "seriousness of purpose was perpetually matched by humility, warmth, and good cheer."
"And that's one reason he became not only one of the greatest senators of our time, but one of the most accomplished Americans ever to serve our democracy," the president stated.
Following Kennedy's death Tuesday and the death of Eunice Kennedy Shriver on Aug. 11, Jean Kennedy Smith, 81, is now the only surviving child of Joseph P. Kennedy and Rose Kennedy's nine children.
Kennedy, who married twice and divorced once, is survived by his widow, three children, and five grandchildren.