Updated: 11:36 a.m.

Senators across the political spectrum were mourning the loss of their colleague Robert Byrd (D-W.Va.) on Monday, remembering him as a friend and mentor who shaped the institution.

Majority Leader Harry Reid called Byrd, who died early Monday morning at 92, “one of the greatest minds the world has ever seen.”

“The people of West Virginia have lost a dedicated public servant, and America has lost a great defender of its most precious traditions,” Reid said. “He was the foremost guardian of the Senate’s complex rules, procedures and customs, and as leader of both the majority and the minority caucuses in the Senate he knew better than most that legislation is the art of compromise.”

Added the Nevada Democrat: “By virtue of his endurance, Robert Byrd knew and worked with many of the greats of the United States Senate. Because of his enduring virtue, he will be remembered as one of them.”

Sen. Jay Rockefeller (D-W.Va.), Byrd’s longtime home-state colleague, said: “It has been my greatest privilege to serve with Robert C. Byrd in the United States Senate.”

“I looked up to him, I fought next to him, and I am deeply saddened that he is gone,” Rockefeller said. “He leaves a void that simply can never be filled.”

Indeed, the loss could not be overstated for many of Byrd’s colleagues who served with him for part of his 51-year Senate career.

Sen. Patrick Leahy (D-Vt.) called Byrd “a Senator’s Senator.”

“Others will speak of his records for time served in the Senate and in Congress and for the number of votes he cast,” Leahy said. “I know him as a mentor and a friend.”

Rules and Administration Chairman Charles Schumer (D-N.Y.) touched on Byrd’s knowledge of Senate procedure.

“I had the privilege to hear him at one of his last appearances when he came before the Senate Rules Committee to discourse on the filibuster just one month ago. As always, his statement was passionate, erudite, balanced and electrified the room,” Schumer recalled. “It’s a moment no one who was there will forget.”

Minority Leader Mitch McConnell (R-Ky.) noted Byrd’s “fighter’s spirit, his abiding faith, and for the many times he recalled the Senate to its purposes.”

“Generations of Americans will read the masterful history of the Senate he leaves behind, and they will also read about the remarkable life of Robert Carlyle Byrd,” McConnell said.

The outpouring for Byrd stretched across the Dome as well.

House Appropriations Chairman David Obey (D-Wis.) said of Byrd: “They really don’t make them like him anymore.” Byrd formerly served as Senate Appropriations chairman.

And the longest-serving House Member, Rep. John Dingell (D-Mich.), said Byrd leaves behind “a legacy of service that bore witness to some of the great changes which have come to redefine our nation.”

Dingell also said Byrd, who came from humble beginnings and put himself through law school while he was a Senator, “was a tenacious defender and advocate for the working class.”

Speaker Nancy Pelosi (D-Calif.) also remarked on Byrd’s life story.

“His story was the true embodiment of the American dream,” she said. “An orphan at a young age, Senator Byrd refused to allow his circumstances to limit the reach of his potential, his ability, or his drive to succeed. … In doing so, he would ultimately make America a better place for every American.”

And, Rep. Shelley Moore Capito (R-W.Va.), who considered challenging Byrd in 2006 and who some speculate may run for the seat in 2012, noted Byrd’s contribution to West Virginia.

“Whether he is remembered as the young man who played the fiddle or the elder statesman that carried a copy of the Constitution in the pocket next to his heart, Robert Byrd touched the lives of countless West Virginians,” Capito said in a statement. “His service to West Virginia and dedication to our nation’s democracy set an example to which generations can aspire.”