15.6% is currently the percentage of the electoral vote controlled by the combination of NY and CA.
You are conflating the electoral vote with the population vote though.
If we took away the electoral college, and relied solely on the popular vote. CA and NY would have the power to elect every President.
The electoral college prevents us from being ruled by just these 2 states alone.
But now there is a new element.
National Popular Vote Interstate Compact - Wikipedia
In which several states are trying to circumvent the electoral college system. I haven't spoke out because it's just a foolish idea by the DNC. With this system it makes it to where a typically blue state can go red. Which is hilarious, so I'm just hoping they get it done!