Sure, but politicians running for national level positions (i.e. President) run a single campaign, and they have to select a single position set for that campaign (1).

You're right that the game theory is more complicated than it would be in a national popular vote contest, but I suspect that the optimal position isn't all that far off from where it would be in a single nationwide Hotelling game.

(1) Mostly, at least, I know they can of course run different ads and given different speeches in different states, flip flop, etc, but their reputation and messaging is inevitably going to bleed across state lines / time quite a bit.