An interesting piece, worth reading, that claims that Pat Buchanan's 1970 memo to his then boss Richard Nixon started the dirty tricks and imperial presidency into action.
I'd take it with a few grains of salt; as was seen during his time as a Senator, and as Eisenhower's VP, Nixon had absolutely no qualms about bare-knuckles fighting and ignoring the law when it suited him to do so.
But it bears remembering that three of the most influential voices in the Republican Party in the last thirty years- Rumsfeld, Cheney and of course Buchanan- got their start with Nixon.
And all three agreed with the concept of permanent war against anyone and everyone who wasn't them- by any means necessary.