What made Addington a fascist?

His abusive authoritarian father.

And we have to suffer the results of his warped upbringing.

"Why, of course, the people don't want war," Addington said.
"Why would some poor slob on a farm want to risk his life in a war when the best that he can get out of it is to come back to his farm in one piece?"
Naturally, the common people don't want war; neither in Iraq or Iran nor in America.
That is understood.
But, after all, it is the leaders of the country who determine the policy and it is always a simple matter to drag the people along, whether it is a democracy or a fascist dictatorship or a Parliament or a Communist dictatorship."
"There is one difference," it was pointed out. "In a democracy the people have some say in the matter through their elected representatives, and in the United States only Congress can declare wars."
"Oh, that is all well and good, but, voice or no voice, the people can always be brought to the bidding of the leaders. That is easy.
All you have to do is tell them they are being attacked by another 9/11 and denounce the pacifists for lack of patriotism and exposing the country to danger.
It works the same way in any country."