In political folklore, as well as Star Trek geekery, there's the old adage: Only Nixon could go to China.
Nixon was a strong president and made the right call. China was ready to open its doors to American trade, and for at least the first several decades we prospered greatly from this new trading partner.
Cuba's 12 million people are unlikely to form such a huge trading partnership, but Obama's political stroke of genius was one of geopolitics -- both far and near political ramifications of finally ending the Cold War in the Western Hemisphere.