As the Presiding Officer of the Senate may not be fully aware of the parliamentary situation currently facing the Senate, a parliamentary staff sits second from the left on the Senate dais to advise the Presiding Officer on how to respond to inquiries and motions from Senators. The role of the parliamentary staff is advisory, and the Presiding Officer may overrule the advice of the parliamentarian. In practice this is rare, and the most recent example of a Vice President (as President of the Senate) overruling the parliamentarian was Nelson Rockefeller in 1975.
An important role of the parliamentarian is to decide what can and cannot be done under the Senate's Reconciliation process under the provisions of the Byrd Rule. These rulings are important because they allow certain bills to be approved by a simple majority, instead of the sixty votes needed to end debate and block a filibuster. A meeting to screen a draft bill by the Parliamentarian Office staff in the presence of Republican and Democratic staff is sometimes informally termed a Byrd Bath.
The office also refers bills to the appropriate committees on behalf of the Senate's Presiding Officer, and referees efforts by the ruling party to change the Senate rules by rulings from the chair. The parliamentarian is appointed by and serves at the pleasure of the Senate Majority Leader. Traditionally, the parliamentarian is chosen from senior staff in the parliamentarian office, which helps ensure consistency in the application of the Senate's complex rules. The last two parliamentarians have served under both Republican and Democratic Senate rule.
The Parliamentarian's current salary is $171,315 per year.[dead link]
The current parliamentarian is Elizabeth MacDonough, who has held the office since 2012, and was appointed by then Senate Majority Leader Harry Reid. Seven people have served as Senate Parliamentarian: