How did the Expoline handle the crowds for the first USC game. Hopefully well.
They have been doing it for quite a while now. They run the shortest headway possible for light-rail and have waiting lines for the platforms, limiting the number of people on the platform to the capacity and therefore efficiently handling about 10k passengers doing a round-trip (corresponding to 20k ridership for the USC / Expo Park and Expo/Vermont Stations).
Rail obstructionists should accept the fact that at-grade rail deserves as much chance as the at-grade automobile.