“ In 1965, petitioner again sought habeas corpus in the District Court, requesting an evidentiary hearing. As supplemented, the application alleged facts relevant to the admissibility of the confession which were not brought out at trial, and which, if proved, presented a stronger case that the confession was coerced. [2] The District Court denied the application without conducting an evidentiary hearing, noting that the issue of coercion had been adjudicated in the prior habeas proceeding. ”

“ Townsend v. Sain substantially increased the availability of evidentiary hearings in habeas corpus proceedings, and made mandatory much of what had previously been within the broad discretion of the District Court. ”