A recent National Geographic article tackles this question by summarizing a pending permit request before the U.S. Fish and Wildlife Service (USFWS).
Before USFWS is a request to bring into the United States the head of an endangered black rhino from Namibia. (International law generally prohibits the trade of rhino parts; a special permit is needed to import them.) The person seeking the permit won an auction to kill the rhino during Namibia’s hunting season and Namibia’s game managers selected an aged male rhino for this purpose. (Each year Namibia auctions off a limited number of permits to hunt designated rhinos.)
To get the USFWS permit, an applicant must show that (1) the rhino was killed for conservation purposes and (2) bringing the rhino into the United States furthers that cause. Supporters of granting these permits argue that this type of hunting helps fund conservation efforts. The auction proceeds help fund grants for rhino conservation, such as anti-poaching efforts. But opponents argue that the practice of killing endangered species to help save them attaches a high value to their death.
According to the article, the USFWS has approved these types of permits in the past and the permit requests generally receive little attention. But this specific case has received over 15,000 comments. The USFWS decision is expected soon.