If the tenant is in breach of the lease, they can be evicted, even if they are paying rent. If the tenant is being evicted because of a complaint the filed with the housing authority, then that could be considered a retaliatory eviction.
Yes, it is possible to evict a tenant even if a tenant is paying rent if there is any legal basis such as breach of a lease or rental agreement. However, if the tenant is being evicted because of filing a complaint discrimination complaint with the housing authority, then it could be considered a retaliatory eviction. For more information, see:
https://www.dca.ca.gov/dca/publications/landlordbook/retalitory-actions.shtml