"The original Legislative Drafting Service, established by Section 1303 of the Revenue Act of 1918, was a single agency composed of two independent branches, one under the direction of the Senate and the other under the direction of the House. In 1970, the House Office of Legislative Counsel was given its own separate legislative charter, but the Senate Office of Legislative Counsel continues to operate under the authority of the original statutory mandate. […] The office is under the direction of the Legislative Counsel of the Senate, who is appointed by the President pro tempore of the Senate, 'without reference to political affiliations and solely on the ground of fitness to perform the duties of the office.' The Legislative Counsel is empowered to appoint senior and assistant counsels, clerks, and other employees 'necessary for the proper performance of the duties of the Office.' In 1999, the Legislative Counsel was given the authority to designate a deputy legislative counsel to serve during his absence or disability or when the position of Legislative Counsel is vacant. The professional staff of the office also includes approximately 30 attorneys and an administrative support staff."
CRS Report for Congress, RS20856