The Obama administration embarked on a new strategy on Thursday to challenge voting laws it says discriminate by race, an effort to counter a Supreme Court ruling last month that freed states from the strictest federal oversight. Attorney General Eric Holder vowed to start in Texas, a conservative stronghold. Texas' voter ID law requires voters to show a photo ID before casting a ballot, a measure its supporters, mostly Republicans, said is necessary to prevent fraud. Democrats said it would disproportionately affect the poor and minorities because even getting a free photo ID would require travel to a state office...