'Sasha" is a nickname or short form for Natasha. One of the instructors at Norwich once told me that a beginning student once answered the usual question as to why any interest in Russian thus: "My grandparents were communists, my parents are comunists, I'm a communist, and I want to be able to read Marx in the original language!" The instructor said he didn't have the heart to tell her and somehow or other kept his face straight, but it must have been hard.
Actually it's a diminutive of Aleksander or Aleksandra. In Russia you'll find both boys and girls being called Sasha.
I have no idea why the Obama's started calling Natasha 'Sasha' but there are a lot of things about them I don't understand.
He probably was planning to read the writings of Groucho Marx ... which would have probably made more sense then reading communism in its 'original language' (or any language, for that matter)...
My dog was named Sasha...She was a fluffy, snow white cockapoo. Not sure why I decided on that name...but it must have come from my somewhere in my Russian background. Both my grandparents were Russian.
Poor student. He didn't that Marx wrote in German.