Via Tom Phipott, who comments:
What Carter actually did was deregulate the home-brew market—he made it legal to sell malt, hops, and yeast to home brewers. That, I believe was a significant move, because the US craft-beer industry was largely started by enthusiastic home brewers who went pro.
E.D. Kain, Erik Loomis, and Matt Yglesias all expand on Philpott's post.
The Dish 