Wisconsinites leaned Democratic when they went to the polls last month, voting to re-elect President Obama, choosing Tammy Baldwin to be their new United States senator and casting more total votes for Democrats than Republicans in races for Congress and the State Legislature. But thanks in part to the way that Republicans drew the new Congressional and legislative districts for this year’s elections, Republicans will still outnumber Democrats in Wisconsin’s new Congressional delegation five to three — and control both houses of the Legislature. Pennsylvanians also voted to re-elect Mr. Obama, elected Democrats to several statewide offices and cast about 83,000 more votes for Democratic Congressional candidates than for Republicans. But new maps drawn by Republicans — including for the Seventh District outside Philadelphia, a Rorschach-test inkblot of a district snaking through five counties that helped Representative Patrick Meehan win re-election by adding Republican voters — helped ensure that Republicans will have a 13-to-5 majority in the Congressional delegation that the state will send to Washington next month.
Republican-drawn lines also helped Republicans win lopsided majorities in other swing states Mr. Obama won: Democratic Congressional candidates won nearly half the votes in Virginia but only 27 percent of its seats, and 48 percent of the vote in Ohio but only a quarter of its seats.
Last month’s Congressional elections were the first to be held in new districts that were drawn across the country after the once-a-decade process of redistricting, when many state officials, charged with redrawing their district maps to account for population shifts, indulge in carefully calculated partisan cartography aimed at giving their party an edge.
Republicans had the upper hand: thanks to the gains they made in 2010 state-level elections, Republicans controlled the redistricting process in states with 40 percent of the seats in the House, Democrats controlled it in states with 10 percent of the seats, and the rest of the seats were drawn by courts, states with divided governments or commissions.