The Center for Health Transformation, Newt Gingrich's health-care think tank, has filed for bankruptcy. The organization listed between $1 million and $10 million in liabilities to between 50 and 90 creditors and will be liquidating its assets. The demise of his think tank has been taken as a sign by some that Newt's presidential bid is on the same track. "This ends his campaign. He'll be completely on the defensive about this," said Merle Black, a professor of political science at Emory University.