Assad deserved to be overthrown, but Obama had not one thing to do with the rebellion against Assad. Syrians just tired of the Assad family,m that had ruled rather brutally since 1971. There were no fans of Assad among the GOP when the rebellion began, either.
Syria is a mess, but a mess caused by Syrians. And when this is over, it will be resolved by other Syrians.
It is in many ways like the civil war in Lebanon, except that was complicated by the Israeli invasion.
Just imagine how you would feel bring ruled by Obama for 44 years.