Citing top-secret documents on the threat of a terrorist attack, Sen. Mark Dayton, D-Minn., shut down his Washington office through Election Day, and on Tuesday urged citizens to avoid Capitol Hill, an act that generated controversy in Washington and beyond.
''I do so out of extreme, but necessary, precaution to protect the lives and safety of my Senate staff and my Minnesota constituents,'' Dayton said.
Dayton said he acted after reading a classified memo that was available to all U.S. senators, but that he couldn't discuss its contents. No lawmakers in the Senate or House of Representatives appeared to follow suit, and many privately said they were startled by Dayton's actions.
''There is no evidence to suggest today that we should be closing the office of a sitting U.S. senator,'' said Erich Mische, the chief of staff to Sen. Norm Coleman, R-Minn. Top Senate and House officials, as well as the U.S. Capitol Police, reiterated that stance.
''There's no new intelligence that I'm aware of at all that would change things in the last month or two in the Senate,'' said William Pickle, the Senate's sergeant at arms, who has oversight of the Capitol Police and works with intelligence agencies. Still, he added, the closing ''generated an awful lot of calls'' from jittery Capitol Hill offices.
A senior FBI official said the bureau remained concerned about an attack before the November election, but that there was no new information pointing to a time or place. There's also no specific information pointing to an attack on Capitol Hill, the FBI official said, speaking on condition of anonymity.
Law enforcement officials have been warning since last spring about a possible strike before the presidential elections by terrorists who may have been emboldened by the train bombings in Madrid last March, which helped turn the tide in Spain's elections.
On a practical level, the closing of Dayton's office will have minimal impact. The House and Senate largely wrapped up their pre-election business Monday, save for a one-day session scheduled for Oct. 20. Lawmakers are scheduled to return after the Nov. 2 election for a short wrap-up session.
The timing of Dayton's action led to feverish speculation -- but few facts -- about whether closing his office had more to do with the upcoming election than with terrorism.
''None of us can predict the future,'' Dayton said in a lengthy statement that was taped to his office door. ''I hope and pray that the precautions I have taken will prove unnecessary.''