Spock gets to be the left-wing character, being an alien. He's from an alien race that Earth has an uneasy alliance with. It might be like how in OTL Star Trek, the Vulcans made first contact with humanity right after the successful warp drive experiment. Perhaps the ATL Vulcans represent the Western world or America.
Maybe switch the Romulans with the Vulcans? See the horrible movie Nemesis?