WASHINGTON -- With Democrats plotting to make the minimum wage a major issue in this fall's congressional races, House Republican leaders are conceding that they may have to yield to pressure for an increase to the federal standard, which has been frozen for nearly a decade. Faced with elections that could cost them control of Congress, John A. Boehner, the House majority leader, acknowledged Thursday that Republican leaders are likely to reverse course and hold a vote on a proposed minimum wage increase. Though Boehner said it was a ``cynical ploy" for Democrats to make it a campaign centerpiece, polls...