It is a neat phrase -beat you like a or slap you like a - if casual beatings delivered on the undeserving are your thing - and who doesn't like that now again again.
The actual etymology, though uniquely southern takes its origin from Irish immigration to the new World (remember the great Mel Brooks joke from Blazing Saddles - 'We'll take the niggers and the chinks, but we won't take the Irish.' The Irish were socially scaled below pretty much everyone else - which in the early days of America is saying something. Red-headed usually indicated a birth of bastardry and the step child, well what classic tale every starts with fun and joy for anyone's step child.
Not in wide use anymore, but interesting in origin.
The actual etymology, though uniquely southern takes its origin from Irish immigration to the new World (remember the great Mel Brooks joke from Blazing Saddles - 'We'll take the niggers and the chinks, but we won't take the Irish.' The Irish were socially scaled below pretty much everyone else - which in the early days of America is saying something. Red-headed usually indicated a birth of bastardry and the step child, well what classic tale every starts with fun and joy for anyone's step child.
Not in wide use anymore, but interesting in origin.