Authentic. And by all accounts, he was drunk-dialing in '64. Think you can hear a belch at some point.

Edit: if I recall correctly, he liked to drive people around his ranch while drinking whiskey out of a styrofoam cup, with lots of ice. When he needed a refill, he'd stick his hand out the window and shake the cup, at which point a secret service agent would sprint from the car pacing behind him to fetch him a refill.

And then there was the thing where he liked to drive new guests into a lake to scare them, since they didn't know about his amphibious vehicle, but that's a different story.

LBJ's home office in Texas was preserved, and is still on display as-is to this day. On the couch is a pillow embroidered "This is my ranch, and I do as I damn please!"