Can a federal court request an attorney to represent a plaintiff proceeding in forma pauperis?

Under 28 U.S.C. 1915, a district court may "request an attorney to represent" a civil litigant proceeding in forma pauperis. 28 U.S.C. 1915(d) (1979). A district court may only designate counsel pursuant to section 1915(d) in exceptional circumstances. Wilborn v. Escalderon, 789 F.2d 1328, 1331 (9th Cir.1986) (internal quotations and citations omitted). A finding of exceptional circumstances requires an evaluation of: (1) "the likelihood of success on the merits;" and (2) "the ability of the petitioner to articulate his claims pro se in light of the complexity of the legal issues involved." Id. (internal quotations and citations omitted).