I haven't lived in SoCal in many years, but those north of Camp Pendleton and south of the grapevine could have given two shytes about the Chargers before 1987(when I left). The big town rivalry was between the Rams and the Raiders for obvious reasons. Normally, Rams fans hated the Raiders because they invaded our turf...Chargers? Who cares about the team from San Diego? That's why it always amused me when those who didn't want the Rams relocation to be successful, kept pointing to the Chargers as though they would embarrassingly take LA fans from supporting the Rams. The truth is the large Raider fan base in LA will definitely never become fans of a chief AFC West rival like the Chargers. Just as if the 49ers moved to LA, would/could Rams fans support their sorry @sses?
The big rival to the Chargers for remaining LA fans will still be the Las Vegas Raiders. The Rams have a built in advantage in LA for all of the years of being located there. Plus, it appears to me we have shifted in a winning direction.
Moving from San Diego may be the worst decision Spanos ever made, if he can't coax the spurned San Diego fanbase to head 100 miles north to support them in Inglewood.