Can a plaintiff recover fees on fees incurred while pursuing the underlying merits of the civil rights action?

Title 42 U.S.C. Sec. 1988 ("Fees Act") provides that in federal civil rights actions "the court, in its discretion, may allow the prevailing party, other than the United States, a reasonable attorney's fee as part of the costs." Recoverable attorney's fees may include fees incurred while doing work on the underlying merits of the action ("merits fees") as well as fees incurred while pursuing merits fees ("fees-on-fees"). Clark v. City of Los Angeles, 803 F.2d 987, 992 (9th Cir.1986). The district court ruled that plaintiffs could recover fees-on-fees only to the degree that their underlying application for merits fees was successful. The issue in this case is whether the district court erred.