They need to sue for religious oppression. They need to sue for breach of contract. When they took those jobs, there was no requirement to violate their faith in the execution of their jobs.
That WOULD be interesting to see as class action... but in Calvinball courts the goal is not the goal.
The headline of this article is “County Clerks Resign Nationwide After Gay Marriage Ruling”. They then list less than 10 County Clerk employees nationwide who resigned. At last count there were 3,143 County and County-equivalents (Parishes, boroughs, etc.) in the US If you assume that each County Clerk’s office has 10 employees (the one listed here had 3, I assume LA County has a LOT more), this comes to 31,1430 employees, of which 10 resigned. This comes out to 0.03%. Truly a groundswell of epic proportions.