a negative vote in committee to block a nomination, a nominee may be filibustered once debate has begun in the full Senate. No nomination for associate justice has ever been filibustered, but President Lyndon Johnson 's nomination of sitting Associate Justice Abe Fortas to succeed Earl Warren as Chief Justice was successfully filibustered in 1968. A president may also withdraw a nominee's name before the actual confirmation vote occurs, typically because it is clear that the Senate will reject them, most recently Harriet Miers in 2006. Once the Senate confirms a nomination, the president must prepare and sign a commission, to which the Seal of the Department of Justice must be affixed, before the new justice can take office. [ 70 ] The seniority of an associate justice is based on the commissioning date, not the confirmation or swearing-in date. [ 71 ] Before 1981, the approval process of justices was usually rapid. From the Truman through Nixon administrations, justices were typically approved within one month. From the Reagan administration to the present, however, the process has taken much longer. Some believe this is because Congress sees justices as playing a more political role than in the past. [ 72 ] When the Senate is in recess, a president may make temporary appointments to fill vacancies. Recess appointees hold office only until the end of the next Senate session (at most, less than two years). The Senate must confirm the nominee for them to continue serving; of the two chief