Ramesh Ponnuru at National Review Online is reporting that Senator Lincoln Chafee has joined with the Democrats (including Senator Jack Reed) to filibuster this year's Defense Department appropriation until a provision allowing oil-drilling in the Arctic National Wildlife Refuge is removed.
By the way, to read a more sensible approach to energy policy, click here.
UPDATE:
The Associated Press confirms ANWR oil-drilling as the reason for the filibuster. (h/t Kathryn Jean Lopez).