Salena Zito

Democrats in West Virginia are gravely concerned about the health of their senior U.S. senator, 91-year-old Robert Byrd, who has been hospitalized since May with a series of infections.

“We are just praying for him to get back to the Senate real soon,” said Nick Casey, West Virginia Democratic Party chairman.

Byrd’s absence has caused distress among supporters and speculation about who would fill his seat if he is unable to return to work.

As the Senate president pro tempore, Byrd is third in the presidential succession line, behind Vice President Joe Biden and House Speaker Nancy Pelosi. He is the longest-serving senator in history, in office since 1959. Communities around the state bear evidence of his work, from federally funded projects to buildings bearing his name.

Since November, Byrd’s power has dwindled along with his health -- as evidenced by his spotty chamber attendance and his quiet relinquishment of the chairmanship of the Appropriations Committee.

Byrd’s Washington office has been mostly mum on details of his illness and where he is receiving treatment. His press office periodically releases updates saying he is recovering from an infection, in constant contact with his staff and expected back at the Capitol soon.

Should Byrd's seat become vacant before his term ends in 2012, that would create the first non-incumbent Senate race in West Virginia since 1984 when Jay Rockefeller, a Democrat, won his seat. Democratic Gov. Joe Manchin would appoint a replacement to serve until a special election is held.

State law requires candidates to go through primary and general elections for the seat, so the earliest that process could begin would be the 2010 spring primary, leading up to a November general election for the remainder of Byrd's term. The seat then would be up for election in 2012.

Republicans are eyeing the seat from a political disadvantage: Democrats hold the governor's office, a majority in the legislature and two of the state's three congressional seats. Still, it's a state that hasn’t voted Democrat in a presidential election since 1996. Last year, President Obama lost to Sen. John McCain by 13 points.

University of Virginia political science professor Larry Sabato said Manchin "could appoint himself, or rather have an agreement with his successor to do so, but that’s unlikely,” since such moves often cause political backlash with voters.

It’s “better to appoint a seat-warmer and run in 2010,” he said. “Manchin is popular and could win it, scandal aside, and in West Virginia scandal is background noise.”

Salena Zito

Salena Zito is a political analyst, reporter and columnist.