Appearing fragile and speaking with a tremor, 92-year-old Sen. Robert Byrd spoke for 15 minutes at last week’s Rules and Administration Committee hearing on filibuster reform. Taking his perch on the dais with the help of a staffer and a wheelchair, the West Virginia Democrat delivered a prepared statement to a room of onlookers who seemed to hang on every word.

“It was a hallowed moment that those of us who were there will not soon forget,” Rules Chairman Charles Schumer (D-N.Y.) later said.

The sight was indeed a rare one for the aging Byrd.

The longest-serving Member’s participation in the chamber has waned in recent years, and particularly in recent months. So far this Congress, he’s voted just 46 percent of the time, his appearances on the floor and in hearing rooms are few and he speaks publicly far less often. Even his colleagues have little or no contact with him.

“I just think he had a couple of bad hits health-wise, but he’s back now,” Sen. Tom Harkin (D-Iowa) said. “I think he’s going to be engaged for as long as he can be.”

It was just one year ago that Byrd was hospitalized for six and a half weeks with a staph infection. And while Byrd’s recovered now, he no longer enjoys the high profile that he once did.

Yet with so many of his priorities driving the news cycle — the mining disaster in West Virginia last month, efforts by Senate Democrats to revamp long-standing floor procedures and a push by President Barack Obama for line-item veto power — Byrd has started to re-emerge.

Last week it was the hearing on filibuster changes; then on Monday, the West Virginia Democrat attacked Obama for seeking great authority to slash spending.

“Congress has the Constitutional authority over the power of the purse and I am not in favor of yet another attempt at a power grab by a Chief Executive,” he said in a statement.

Byrd, a former Appropriations Committee chairman, has long championed Congress’ power of the purse, and on that front he is likely to continue putting up a fight. He won an additional $22 million in the upcoming war supplemental for mine safety in the wake of the West Virginia tragedy and is working with Harkin and others on broader mine safety legislation.

In an e-mail, Jesse Jacobs, Byrd’s spokesman, characterized his boss’s recent activities this way: “It is absolutely fantastic that like spring he is reenergized and reinvigorated.”

One source attributed Byrd’s re-engagement to the events around him. Byrd was saddened by the retirement of House Appropriations Chairman David Obey (D-Wis.) and witnessed the recent primary defeat of home-state colleague Rep. Alan Mollohan (D). This source noted that Byrd takes it personally when he witnesses veteran colleagues being replaced by younger, reform-minded lawmakers.

[IMGCAP(1)]”You can go down the list and see the things that matter to him,” the source said. “More and more of his world is changing, and probably not for the best. So these events have wakened the sleeping giant.”

Byrd isn’t new to the idea of being replaced. At the beginning of the 111th Congress — under pressure from some Senate Democrats who didn’t believe he was still up to the job — Byrd voluntarily gave up the Appropriations gavel to his longtime friend Sen. Daniel Inouye (D-Hawaii). He still serves as Senate President Pro Tempore, a position that puts him third in line of succession to the presidency.

Even though Byrd no longer sits atop the Appropriations panel, he seems to know when it’s time to be heard. During last week’s Rules hearing, Byrd took to the microphone to discourage his colleagues from doing away with the filibuster.

“Over the years, I have proposed a variety of improvements to Senate rules to achieve a more sensible balance allowing the majority to function while still protecting minority rights,” he told colleagues. “For example, I have supported eliminating debate on the motion to proceed to a matter (except for changes to Senate rules) or limiting debate to a reasonable time on such motions, with Senators retaining the right to unlimited debate on the matter once before the Senate.”

In a statement, Schumer called Byrd “the leading authority on the rules and traditions of the Senate” and noted the significance of his attendance.

Byrd’s recent Senate participation hasn’t gone unnoticed, but neither have his absences. He missed a crucial procedural vote last month that if successful would have allowed Democrats to kick off debate on financial regulatory reform. Yet Byrd has participated in many of this year’s high-profile floor votes. He cast a vote March 25 in favor of the Senate’s health care bill and afterward could be seen on the floor clasping hands with Senate Majority Leader Harry Reid.

In a statement Monday, the Nevada Democrat said of Byrd: “He has been there whenever we have needed him, including every vote, no matter the hour, on historic health reform legislation.”

On Nov. 18, 2009, Byrd became the longest-serving lawmaker in history. But even at 92, Byrd is still shy of becoming the oldest serving Member. That distinction still belongs to the late Sen. Strom Thurmond (R-S.C.), who retired in 2002 at age 100.

“Sen. Byrd remains active and engaged,” Harkin said. “I know he’s frail, but he’s sharp as ever.”