In this paper we present a case study of a syntactic sociolinguistic variable that has resisted previous attempts at quantitative analysis of usage, the double modal construction of Southern United States English (e.g., You know what might could help that is losing some weight). While naturally-occurring double modals have been exceedingly rare in sociolinguistic interviews, our study represents the very first corpus investigation of double modals through a search of the right ‘haystack’: the nationwide Verilogue, Inc database of recorded and transcribed physician-patient interactions (~85 million words). As a vast source of potentially face-threatening negotiations, the Verilogue corpus provides the ideal speech situation in which to search for low frequency, non-standard syntactic features like the double modal. A quantitative analysis of the 76 tokens extracted from doctor-patient consultations in the US South revealed that double modals are favored by doctors, especially women and those with many decades of professional experience. Among patients, those not currently in employment use double modals more frequently than the employed. We interpreted these findings with reference to the literature on the pragmatics of physician-patient talk, arguing that the double modal is used to negotiate the imbalanced power dynamic of a doctor-patient consultation. In general, the greater use of double modals by doctors shows that the construction is an active part of a doctor’s repertoire for mitigating directives. Collectively, we present a complex socio-pragmatic picture of double modal use that could not be seen without a corpus of naturally-occurring speech in a potentially face-threatening speech situation.