When Florida mailman Douglas Hughes flew his tiny gyrocopter onto the U.S. Capitol grounds a couple of weeks ago, he did more than make a statement on the need for political campaign finance reform.

He also delivered a message to terrorists – our nation’s capital remains vulnerable to attack.

Air defense officials told members of Congress this week that radar picked Hughes’ aircraft up, but it was indistinguishable from other objects such as birds. Capitol police had very little warning Hughes was headed their way.

Once he was viewed as a potential threat, officials did not react in a decisive, coordinated fashion. For example, senators in the Capitol were alerted to a problem – but members of the House of Representatives were not.

Had Hughes been bent on violence, perhaps carrying a bomb or even a gun, his mission could have been a successful surprise attack.

Rep. Jason Chaffetz, R-Utah, chairman of the House Oversight Committee, has said Hughes is “lucky to be alive” and “should have been blown out of the air.”

That would have been unfortunate, knowing what we now do about Hughes. But the disturbing question is why he was not stopped before reaching the Capitol.