Dayton closes down office

Senator Mark Dayton is closing down his Washington office citing security concerns. He does not elaborate on those concerns, only saying that he is the recipient of an intelligence report from Majority Leader Bill Frist. Staff will be working in areas away from Capitol Hill.

What is this? Is this a general threat that only Senator Dayton is publicizing, or is it a threat specifically targeted towards him? Dayton is generally considered to be the most liberal member of the Senate (no, it's not John Kerry), taking up where the late Paul Wellstone left off. It's not inconceivable that some right-wing loonies may be targeting him. Then again, this may be just another example of crying wolf.

A commenter over at Atrios says that rumors are that Dayton will resign shortly for family reasons. I haven't heard these rumors myself, and seeing as how they are from a guy on a website, it could be more nonsense. But it certainly is interesting.