Tom Ridge, in his soon-to-be released book claims that he was pressured to raise the terror threat alert weeks before the 2004 elections. Prior to the election there were video tapes released by bin Laden and Azzam the American (Adam Gadahn) making unspecificed threats against the US and US interest. Ridge is quoted:

“There was absolutely no support for that position within our department. None,” he writes. “I wondered, ‘Is this about security or politics?’

 The book is not out so there's not much else to go on. Hopefully there's more to it than just that as that seems incredibly weak. And not that I want to give the Bushies a free pass, they used terrorism and politics as a two way street to get what they wanted. When the need fit them they used the threat of terrorism canard to improve their political standing and when the intelligence or facts on the ground did not jive with their personal beliefs they used their political strength to pressure for cherry picked reports and analysis which fit their world view. 

 It was a descpicable game to play with American security, one which has probably set back our intelligence agencies and international diplomacy back by a decade. 

So I do find Ridge's allegations believable but the proof has to be more than a "I wondered..." comment. 

 [Addendum] It appears he does go into more detail in the book, claiming it was Rumsfeld and Ashcroft who put the pressure on him. To Ridge's credit he left the administration a month after the elections and did speak out against the terror alert system in 2005. But why wait five years to let this be known? Why do people give themselves up to loyalty to any institution to the point of when that institution behaves illegally or unethically they somehow cannot find their moral compass?