In the mid-1980s, the Senate adopted the Byrd rule, which placed restrictions on what measures can pass through reconciliation, but in recent years, it has been used to pass major entitlement and tax reforms, including multi-trillion dollar Bush tax cuts.
However, decisions about what does and does not conform to the Byrd rule is ultimately not up to the parliamentarian. The parliamentarian's job is to advise the Senate chair--a.k.a. the Vice President--who gets to make the final decision.
"Ultimately it's the Vice President of the United States...It is the decision of the Vice President whether or not to play a role here.... And I have seen Vice President play that role in other very important situations," Dove said, noting that in most cases, the veep defers to his adviser. "I will say that not since Hubert Humphrey have I seen a Vice President try to play that kind of role in the Senate."
These facts will almost certainly come into play soon. Democrats are gearing up to use the budget reconciliation process to pass some changes to the Senate health care bill. Senate Majority Whip Dick Durbin acknowledged this morning that Republicans are simply not going to provide Democrats a single vote, and Democrats will have to go it alone.