By Jonathan Allen, CQ Staff

Sen. Edward M. Kennedy is in Massachusetts General Hospital after suffering a seizure at his Cape Cod home Saturday.

His primary care physician says the senator is “not in any immediate danger.”

Dr. Larry Ronan says preliminary tests showed the 76-year-old Massachusetts Democrat has not suffered a stroke, as news outlets initially reported. Ronan says Kennedy was resting comfortably and would undergo further evaluation to determine the cause of the seizure.

Kennedy, 76, was “conscious, talking, joking with family,” who quickly surrounded him after he was airlifted to Massachusetts General Hospital, spokeswoman Stephanie Cutter said.

Kennedy, the chairman of the Senate’s Health, Education, Labor and Pensions Committee, has carved out a reputation as one of the Senate’s foremost dealmakers despite a voting record and national profile that cast him as the chamber’s leading liberal warrior.

He is the second longest-serving among current senators, ranking behind nonagenarian West Virginia Democrat Robert C. Byrd .

He took his Senate seat — the one once held by his brother John F. Kennedy — in 1962 upon reaching the Constitution’s age requirement of 30. A family friend, Ben Smith, kept the seat warm for the younger Kennedy after his brother was elected president in 1960 and before he was eligible to serve in the Senate.

He is the last surviving son of Joseph Kennedy — his brother Joseph P. Kennedy Jr. was killed in World War II; John and former New York Sen. Robert F. Kennedy were both assassinated in the 1960s — and the father of Rep. Patrick Kennedy, D-R.I.

Kennedy, a Democratic superdelegate, is backing his Senate colleague, Illinois Democrat Barack Obama , for president.

“Obviously our thoughts and prayers are with Ted, who is one of my favorite people,” Obama said, adding that he had called Kennedy’s wife, Vicki, to learn more about what was going on.

Obama’s Democratic primary opponent, Sen. Hillary Rodham Clinton of New York, and presumptive Republican nominee, Sen. John McCain of Arizona, also released messages of concern and support.

“My thoughts and prayers are with Sen. Ted Kennedy and his family today. We all wish him well and a quick recovery,” Clinton said.

“Senator Kennedy’s role in the U.S. Senate cannot be overstated. He is a legendary lawmaker, and I have the highest respect for him. When we have worked together, he has been a skillful, fair and generous partner. I consider it a great privilege to call him my friend,” McCain said.