Still not a majority

I don't think you understand math. Do you really think that 47% of 18-24-year-olds are the same as 47% of the whole population? Adding 4% to that will not get you 51% because 18-24 is only one small segment of the whole population. That's like saying that 47% of all French are blonde and that if we add just a few more blondes we'll have a blonde majority worldwide.