Don't do it - laminate is a floating floor, completely different. The carpet would need to be stretched with gripperods around the edges anyway so the laminate would be damaged and the carpet will never be right laid like that.
Take the laminate up - took me about ten minutes to take up the horrible laminate in our living room which had been previously carpeted over by tenants. They took the disgusting stained carpet with them and left us with the gripperod edging look!
It's up to you, but carpet should be laid directly on top of the floorboards. With decent underlay I don't see the benefit of leaving the laminate down.
Laminate is a floating floor so if it has been glued down it hasn't been installed correctly in the first place! You may also end up with uneven levels around door frames with carpet over laminate, but if you want to do it, then do it.
I would liken carpet over laminate as wallpaper over wallpaper myself.