Maybe because the USA was not arming the Hutu while arresting Tutsi sympathizers? They didn't prevent Tutsi speakers at DNC? Perhaps voters care when there tax dollars go to a foreign government genocide and why its not going tword a M4A, housing, or public-social investment??
Clinton didn't lose any voters over Rwanda and Burundi where the death toll was much higher and the manner of killing was more brutal even if an intervention could have stopped it. It's good to be for peace, but voters care more about what's in it for them, not misdeeds done by foreigners far away.