The Obama administration maintained Friday that President Bashar Assad shouldn’t lead Syria any longer, rejecting a Russian claim that the U.S. has changed its position.
Here's the deal. The US isn't going to determine Assad's fate, short of WWIII, in which case, the US's goose will be cooked right along with Assad's, as it would very likely lead to global thermonuclear exchange concerning which the US would not be immune.
Assad should have reformed very early while he could have remained in power while appeasing the protesters who appealed to the average American. Assad, however, was afraid of al Qaeda waiting in the wings, which it was (plus ISIS, which hadn't completely surfaced yet).
The one and only correct position for the US at this time is to say that the Syrian people will decide Assad's fate via a general election supervised by leading, international election-supervisors. If Assad wins, he stays. End of story.