We test whether emphasizing foreign aid's ability to advance donor national interests increases public support for aid. We compare appeals to the national interest with other approaches, including highlighting aid's ability to help developing countries. Tests involved a nationally representative, randomized survey experiment in which the treatments were vignettes about a major real aid project. Central among our findings were asymmetric treatment effects. It was easier to reduce the view that too much aid is given than to increase the belief that too little is given. Only appeals to the national interest were reliably able to do the latter. The efficacy of the different treatments varied depending on participant ideology, although in unexpected ways.