I read in books not to play split kings against a raise from an ace. However, when the ace completes with just a K and the bringin to act, I see the K raising. In this case, the ace is probably completing with any hole cards. It seems like a clear raise with buried kings and a low card showing, but what about with split kings? How often would you raise the ace as the bringin if the K folded?

How many kings and aces are left?
Do you have a 2-flush? If so, how many of that suit are left?
How low is your low card?

Novice advice:
The books advocate folding KK when an ace raises not only because they could have AA already, but also because they can end up freerolling a low against you and end up catching high as well for the scoop.

If 2-3 aces were already folded I'd come in for a re-raise and apply pressure if they catch bad, and back down if they catch good (low cards) since they could easily be free-rolling you at that point.
If one ace is gone you could see 4th street and then put in a raise if they catch bad.
If all aces are live I think it's best to just fold.

Also depends on ante structure and who the bring in is. It's not a clear cut decision

I have another take: Unless the raiser is an ABC unimaginative type, IOW a decent player, I think it's worth a few dollars here and there to re-raise just to let them know that I won't roll over automatically esp in a game against regs.