House Republicans plan to ratchet up scrutiny of the IRS during a hearing Thursday morning where agency workers are expected to discuss the involvement of high-level officials in slowing down applications from Tea Party groups. For the first time, the House oversight committee has invited two key agency officials to testify. Republican leaders of the committee claimed Wednesday that one of them recently revealed that the IRS chief counsel's office -- led by a political appointee -- played a role, along with embattled IRS official Lois Lerner, in scrutinizing conservative groups. Rep. Darrell Issa, R-Calif., chairman of the committee, told...