The puzzle has finally been solved  -- President Obama's terrible debate performance last week was all Michelle Obama's fault ... at least according to "Saturday Night Live."

Last night SNL spoofed Obama and Romney's initial showdown -- offering one hysterical explanation for POTUS (played by Jay Pharoah) choking: he was really thinking about a last minute anniversary gift for the First Lady.

Coffee mug? Denver Bronco's sweatshirt? Bathrobe?