"I want to take a moment to say how distraught and terribly shaken I am over the news of my dear friend, my dear, dear friend, dear friend, Ted Kennedy," Byrd said as he began to cry. "My thoughts and my humble prayers are with Sen. Kenney, my dear friend Ted, with his wife Vicki, and with the members of the Kennedy family. I hope and pray that in an all-caring omnipotent god will watch over Ted and keep Ted here for us and for America. Ted, Ted, my dear friend, I love you and I miss you and Erma, Erma, Erma, my darling wife Erma, I want to say, thank god for you Ted, thank god for you."
Sen. John Kerry, D-Mass., called his colleague from Massachusetts "one unbelievable fighter," saying when he visited Kennedy over the weekend the senator, who endorsed Kerry's bid for the White House in 2004, was in a "fighting mood."
Gov. Arnold Schwarzenegger, R-Calif., whose wife is a member of the Kennedy family, issued a statement, saying, "Maria and I are thankful for everyone's thoughts and prayers today and over the past several days. While we are still learning the extent of Teddy's diagnosis and treatment options, what we do know is that Teddy is an incredibly courageous and tenacious man who will tackle this with the same determination with which he approaches everything in life. I encourage everyone to keep Teddy in their prayers, as we are continuing to do."
President Bush was informed by staff about Kennedy's brain tumor Tuesday afternoon. White House spokeswoman Dana Perino said the president was "deeply saddened" and would keep him in his prayers.
Sen. John McCain, R-Ariz., the presumptive Republican nominee for president, a cancer survivor, responded to the news aboard his campaign bus in Florida.
McCain's campaign also released a statement praising Kennedy, saying, "I have described Ted Kennedy as the last lion in the Senate, and I have held that view because he remains the single most effective member of the Senate."
Kennedy, the last of three brothers who changed the American political scene in 1960s, was taken by ambulance to a Cape Cod hospital Saturday morning and later flown to Massachusetts General Hospital by helicopter.
"Preliminary tests have determined that he has not suffered a stroke and is not in any immediate danger," Kennedy's physician, Dr. Larry Ronan, said Saturday evening. "He's resting comfortably and watching the Red Sox game with his family."
Kennedy's wife, Vicki, was with him at the hospital, Kennedy family spokeswoman Stephanie Cutter said.
Several other members of the senator's family visited him at the hospital, including his three children, Kara, Edward Jr. and Rep. Patrick Kennedy, D-R.I., niece Caroline Kennedy and nephew, former Rep. Joseph P. Kennedy II.
He spent much of the afternoon watching sports on television: first the Boston Red Sox game, then the Boston Celtics' playoff game against the Cleveland Cavaliers. Kennedy went to Cape Cod Hospital Saturday "after feeling ill at his home" in Hyannisport, Cutter said.
"We got a 911 call at 8:19 a.m. [Saturday] morning for a request for an ambulance," Lt. Bill Rex, a spokesman for Hyannisport Fire and Rescue, confirmed to ABC News Saturday. "We transferred one male to Cape Cod Hospital in Hyannis."
Kennedy's doctors in Boston were contacted, and it was decided he should be taken to Massachusetts General Hospital for further testing.