Plenty of the choices facing the wine world are hard. Making wines with "American" on the label 100% from US grapes shouldn't be one of them.
California AB 1585 would require that any wine that says "American" on its label and is produced, bottled, labeled, or sold in California be sourced 100% from American grapes. It might not be a game-changer for struggling growers or for consumer transparency, but it seems like a good start.