Each state must redraw its political maps to reflect the 2010 census, but New York, which has approved neither legislative nor Congressional districts for this year's elections, is among the last to comply. Redistricting has become increasingly urgent because of the calendar; the state's Congressional primary is scheduled to be on June 26, and its legislative primary on Sept. The State Legislature has proposed new districts for the Assembly and the Senate, but those districts have been criticized as gerrymandered to protect incumbents, and the Legislature has not voted on the proposals. The Legislature has not proposed new maps for the state's Congressional districts, which must decrease to 27 from 29 as a result of the census. In federal court in Brooklyn on Monday, a panel of judges began to take control of the Congressional portion of the redistricting process. They instructed a magistrate, Roanne L. Mann, to prepare a map, and set a March 12 deadline for her to furnish a proposal for the judges" consideration. The judges said Judge Mann would function like a special master, and they enlisted Nathaniel Persily, a redistricting expert who is a professor at Columbia Law School, to assist her. The judges said they would be prepared to impose a new Congressional map by March 20, when the petitioning process for prospective Congressional candidates is scheduled to begin. While the federal court works on Congressional districts, legislative leaders are trying to revise their proposed maps for the Senate and Assembly. Meanwhile, on Thursday, a state judge is scheduled to hear arguments over whether to dismiss a lawsuit challenging a proposal by Senate Republicans to increase the size of the Senate to 63 seats from 62. It is a step that Republicans say is required by the State Constitution, but that Democrats say is a political move intended to increase the odds that the Republicans will retain control of the Senate.