Oakland is a joke. It's like this poor, shitty smallish city on the outskirts of San Francisco which is a monster international city. I have no idea where their fans come from.
If this map existed when Al Davis relocated the Raiders to Los Angeles Northern California would be black. The Raiders were selling out every game and were a perrenial playoff team. The 4pers only became mopre popular after hiring Bill Walsh.
There are over 8 million people in the Bay Area. If even 25% of them favor the Raiders that is still more people within a one hour drive than the Saints can claim.