(CNN) -- After a year of hostile debate and partisan cage fights, some of the toughest decisions about health care reform have fallen to one man.
Alan Frumin has worked in relative obscurity for more than 30 years in the office of the Senate parliamentarian.
Frumin, who is serving his second stint in the top post in the office, finds himself in the spotlight now because it is up to him to advise lawmakers on what can and cannot be passed through reconciliation.
Reconciliation is a parliamentary shortcut that allows the Senate to push through legislation with a simple 51-vote majority instead of the normal 60. Under the Byrd rule of 1985, named after Democratic Sen. Robert Byrd of West Virginia, only items related to the budget can be taken up with reconciliation.
Democrats hope to push health care reform through the Senate using the tactic.
"This is probably the most difficult situation for any Senate parliamentarian in my memory," said Robert Dove, who joined the parliamentarian's office in 1966 and served in the top post from 1981 to 1987 and 1995 to 2001. Frumin served from 1987 to 1995, and from 2001 to present day. The parliamentarian is appointed by the party in power.
"I was never under the pressure that Alan Frumin is under right now. I was not on the front page of the New York Times," Dove said.
Frumin's office declined CNN's request for an interview.
Just five men have served as the Senate parliamentarian since the position was created in 1937. Over the past few decades, the duties have "expanded immeasurably," said Dove, who teaches at George Washington University.
The parliamentarian counsels lawmakers on legislative rules and procedure. The parliamentarian or someone from that office sits on the Senate dais and advises the presiding officer when the Senate is in session.
When Dove came on board, he said, most senators knew the rules and precedents pretty well, and therefore the job wasn't a controversial position.
The parliamentarian's role started evolving in the 1970s, Dove said, when Congress decided to enact statutes "that had enormous procedural ramifications," like the Congressional Budget Act and the War Powers Act.
"Suddenly, the parliamentarian was making procedural decisions on issues that I discovered were just absolutely extraordinary," Dove said.
In 1982, Dove was forced to make a decision that he considered "way above my pay grade."
Dove had to decide whether Marines in Lebanon were in imminent danger.
"I decided that they were," he recalled. "A number of senators were very unhappy with that decision, as a number of senators are going to be unhappy with whatever decisions Alan makes."
Frumin advised lawmakers last week that a reconciliation package must be tied to existing law. That means the House must first pass the Senate's health care plan, wait for President Obama to sign it into law and then vote on the package of "fixes" that the president proposed.
In the Senate, those fixes would have to be passed through reconciliation, since Democrats no longer have a 60-seat supermajority, and Frumin will tell lawmakers what parts of the bill don't apply.
"If someone raises an issue about abortion, someone might object and say, 'Well, abortion really isn't a budget matter, and it's not a proper part of a reconciliation bill,' " said Cheryl Block, a budget policy expert and professor of law at Washington University in St. Louis, Missouri.
"Republicans are lined up with all sorts of opportunities to argue that things are extraneous," she said, adding that Frumin is "going to be on the hot seat throughout this whole process."
Dove predicted that this will be the hardest workweek the parliamentarian's office has had since 1995, when he had to chop up a reconciliation bill and toss out about 300 provisions that violated the Byrd rule.
But the parliamentarian's advice is not binding. The vice president, who is also the president of the Senate, can overturn it, as did Hubert Humphrey did in the late 1960s.
"No vice president since then has done that. I would be very surprised to see this vice president do that," Dove said.
Dove said he has the utmost confidence that Frumin will handle the health care legislation well, but he noted, "I do not envy him in the slightest."
It's up to the parliamentarian to dispense nonpartisan advice, but his job is in the hands of the majority party. Then-Majority Leader Trent Lott dismissed Dove in 2001 after rulings he made upset Republicans.
Dove said he looks back on his three and a half decades in Capitol Hill fondly, but, speaking from a beach house of the coast of South Carolina, he said he certainly enjoys not being there now.