House Oversight Chairman Henry Waxman (D-Calif.) has subpoenaed Environmental Protection Agency (EPA) documents involving the White House as part of his committee's investigation of EPA's 2007 decision stating that California could not impose its own stricter regulations on auto emissions.

Waxman said his committee has found evidence that the EPA communicated with the White House about the decision. "Unfortunately, EPA has refused to disclose the substance and extent of its communications with the White House," Waxman said today. "The Committee must have these documents in order to understand how the agency