How have courts interpreted section 1021.5 of the California Constitution on attorney fees?

The enforcement of an existing right "does not mean that a substantial benefit to the public cannot result. Attorney fees have consistently been awarded for the enforcement of well-defined, existing obligations. [Citations.]" (Press v. Lucky Stores, Inc. (1983) 34 Cal.3d 311, 318 (Press).) The "declaration of rights in 'landmark' cases would have little meaning if those rights could not be 'enforced' in subsequent litigation. As this court [previously] noted . . . , 'without some mechanism authorizing the award of attorneys fees, private actions to enforce . . . important public policies will as a practical matter frequently be infeasible.' Such a cramped interpretation of section 1021.5 would allow vital constitutional principles to become mere theoretical pronouncements of little practical value to ordinary citizens who cannot afford the price of vindicating those rights." (Id. at pp. 318-319.)