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I demonstrate that if an anisotropy in the arrival direction of high-energycosmic-ray electrons and positrons is observed then, barring local anisotropicdiffusion, dark matter annihilation is ruled out as an explanation to thepositron excess. For an observable anisotropy to originate from dark matterannihilation, the high-energy electrons and positrons must be produced in anearby clump. I consider the annihilation pathway producing the smallest fluxof gamma rays versus electrons and positrons, and the combination of clumpdistance and luminosity that minimizes the gamma-ray flux. I show that if ananisotropy from such a clump were detected, and if such anisotropy did notgenerate from anisotropic diffusion effects, then the clump would be clearlydetectable as an anomalous, bright gamma-ray source with the Fermi Large AreaTelescope. I also point out that the non-detection of an anisotropy isperfectly compatible with an astrophysical origin for the excess positrons thathas nothing to do with dark matter.

An observable electron-positron anisotropy cannot be generated by dark matter