If I were going to do this I would dedicate all the clothing in that suitcase to protecting the laptop
It will be the underwear you're wearing at the time which will take the strain.
If you have a wee 11" IBM,
and you're using a full-size Delsey or Samsonite,
and it's stuffed to the gills with well-placed clothing with a shell of crushable, resilient material (bubblewrap),
and you don't mind taking the risk that it might go missing, it should be fine. That's how I bring wine over.
Wine bottles are designed to stand up to an amazing amount of abuse, though (unlike laptops), and their footprint is much smaller than the standard widescreen laptop one buys today. When something goes *bump*, they just roll out of the way. Sliding doesn't happen under a compressive load with a laptop.
PAXboy's comment about handling is spot on. I've seen the entire contents of a baggage cart ejected, because the subterranean creature driving the tractor had somehow passed the security checks and nothing else. Eight feet down came the top suitcases onto the all-forgiving Tarmac. Presents for children, souvenirs from a once-in-a-lifetime journey, an heirloom Coronation mug from Grandma - ker-splat.
Your laptop's safety will be in the hands of mechanical sorting devices and baggage handlers - ill paid, mucking around with baggage for people who are off on trips, when it's freezing cold and the supervisor is barking at you to hurry up.
Convinced yet?
BOFH