WASHINGTON – The giant boots of Edward Kennedy wait to be filled in the Senate, where the health care reforms he once described as the "cause of his life" might soon require every vote to pass.
There was no immediately apparent successor to Kennedy, who was the third-longest-serving senator in US history thanks to almost 47 years of service during which he was an outspoken champion of liberal causes.
The governor of Massachusetts backed Thursday a poignant plea made by Kennedy just days before his death for an interim successor to be swiftly appointed.
"I'd like the legislature to take up the bill quickly and get it to my desk and I will sign it," governor Deval Patrick told the Boston Globe in an interview.
With President Barack Obama's sweeping health reforms up for a Senate vote later this year, Kennedy wanted to leave nothing to chance as he knew that every vote might count.
As the succession battle began, experts said there was no obvious candidate for a post the late US senator inherited in 1962 from his brother John F. Kennedy, who was by then in the White House.
"There's going to be an enormous battle among Democrats," said Eugene Dionne, a political analyst from the Brookings Institution think tank. "There's no obvious candidate. It's a state full of ambitious Democrats."
Among the many names being bounced around is that of Joe Kennedy, son of Robert F. Kennedy, who was assassinated while campaigning for the White House in 1968, five years after his elder brother JFK suffered a similar fate.
But neither Joe, not Kennedy's widow 55-year-old Vicki is said to be interested in a Senate bid, meaning the race would be wide open.
"If somebody from the Kennedy family, Joe Kennedy, or his wife Vicki Kennedy want to run, there might be some sentimental feeling in their favor," Dionne said. "But she's saying she doesn't want to run. There's no one obvious."
In the House of Representatives Stephen Lynch, Michael Capuano and Ed Markey have not declared plans but their names have been mentioned as leading Democrats who could potentially be interested.
"Today is not a day for political speculation but rather a day to honor the incredible life and legacy of Senator Kennedy," Daniel Reilly, a spokesman for Markey, told AFP.
Former congressman Martin Meehan has also been mentioned and reportedly has a 4.9-million-dollar campaign war chest. Massachusetts Attorney General Martha Coakley was one of the few women considered in the running.
Norman Ornstein, an analyst at the American Enterprise Institute, said filling Kennedy's boots would be nigh on impossible.
"There is no junior Kennedy coming forward who will have anywhere near the force of John, or Bobby, or Ted. But beyond that, there is no senator coming forward who can plausibly replace Ted," Ornstein said. "It's not just that there is no Kennedy. There's nobody to replace Kennedy in the Senate."
Senior Democrats mourning Kennedy vowed to honor his memory by passing Obama's embattled health care overhaul this year with some even calling for the legislation to carry his name.
But observers warned that Kennedy's death Tuesday from brain cancer, though sure to renew Democrats' passion for the plan, would do little or nothing to alter the dynamics that have bedeviled Obama's chief domestic priority. They argue that Kennedy's passing has silenced an eloquent advocate for the measure and steals a key vote for the legislation, leaving Democrats shy of the 60 votes needed to break through any parliamentary delaying tactics.