I am stumped.

GOOGL (class A shares) are trading ~$1.50 lower than GOOG (class C shares). My understanding is the only difference between the two is the class A shares have voting rights and class C don't, which would normally cause GOOGL to trade very slightly above GOOG not below it.

What am I missing?

Buy whichever one is cheaper. At the end of the day it's not going to matter but you are unlikely to ever have enough shares where your vote matters so just get the one that is cheaper.

Edit: to clarify the price of which one is cheaper goes back and forth. Most of the time the class A is more expensive but sometimes due to the float they flip which is why I say just buy whatever is cheaper