GOP ready to block another key Obama court nominee Republicans seemed ready to block another of President Barack Obama's picks for one of the nation's top courts on Tuesday, the latest skirmish in a nominations battle that has intensified partisan tensions in the Senate. Senators planned to vote on Obama's selection of Georgetown University law professor Cornelia Pillard to fill one of three vacancies on the U.S. Court of Appeals for the District of Columbia Circuit. Majority Democrats were expected to fall short of the 60 votes needed to overcome a GOP procedural blockade against Pillard's nomination. Democrats have been threatening that if Republicans continue derailing Obama's nominations, they might unilaterally rewrite Senate rules to make it harder for the chamber's minority party to do that. It is unclear that Democrats have enough votes to do so, with some senior lawmakers warning that the change would boomerang against them should the GOP recapture the Senate majority and the White House. The D.C. circuit court is generally considered second in clout only to the Supreme Court. It rules on White House and federal agency actions, and some of its judges customarily have been elevated to Supreme Court justices. The D.C. circuit's eight current judges are evenly divided between those appointed by Democratic and Republican presidents. Republicans have accused Obama of trying to tilt the court's balance in his direction to protect the fate of his administration's policies. They say the D.C. circuit has a lighter caseload than other districts, and have proposed legislation eliminating one of its vacant judgeships and moving the two others to busier circuits. Democrats say the GOP objections are purely political and say Republicans did not object to filling D.C. circuit vacancies when George W. Bush was president. They cite other statistics to argue that the D.C. circuit's workload has changed little in recent years. Pillard worked twice in the administration of President Bill Clinton -- at the solicitor general's office, which handles Supreme Court cases, and later in the Justice Department. She'd previously worked for the NAACP Legal Defense and Educational Fund. Two weeks ago, Republicans successfully blocked a vote on Patricia Millett, a private attorney who served in both GOP and Democratic administrations, to the same court. Another Obama nominee for the D.C. circuit, U.S. District Judge Robert Wilkins, is expected to be considered by the Senate in coming days and seems likely to be blocked.