President Obama interviewed federal judge Diane Wood of Chicago today for the Supreme Court opening, the fourth candidate known to have had face-to-face talks with the president. Wood met with Obama in the Oval Office and interviewed separately with Joe Biden. She follows Solicitor General Elena Kagan and federal appeals court judges Merrick Garland of DC and Sidney Thomas of Montana. Others are known to be in the mix, and an announcement is expected any day. (More US Supreme Court stories.)