But it's not entirely his fault — Lehrer kept getting interrupted. While the general consensus seems to be that Romney was the real culprit here, this parody from Late Night With Jimmy Fallon has Obama jumping in, too.
In case you were concerned about his feelings, Lehrer told TMZ that he felt disrespected. (Or rather, they asked a leading question about feeling disrespected and he deflected it. Same thing?)
[H/T Justin Shanes]