It's been a rough past few days for Secretary of State John Kerry. Like, really rough.

Consider the following:

* Less than 24 hours after Kerry made an authoritative case for military action against Syria, President Obama reversed course and decided to take the case to Congress -- a move fraught with political peril.

* Massachusetts Sen. Ed Markey (D), the man who took Kerry's seat, voted "present" on the Syria resolution.

* At a news conference in London today, Kerry called the military action the Obama administration is advocating "unbelievably small." That led Arizona Sen. John McCain, a proponent of a Syria strike, to tweet that Kerry's comment was "unbelievably unhelpful."

Kerry allies note that he has been on the job since Feb. 1 and has successfully navigated any number of difficult situations -- including appearing on all five Sunday shows last weekend and serving as the point man for the administration in making the case on Syria.

And, Obama's decision to reverse course and Markey's "vote" aren't exactly Kerry's fault. Obama quite clearly went against much of the advice from his national security/foreign policy team when he decided to seek congressional approval on Syria. Markey's "vote" was similarly tough for Kerry to control -- although one might have thought the new senator would have been for the measure solely out of loyalty to the current secretary of state.

Still, Kerry's rhetorical stumbles have made an already difficult sales job that much tougher for the Obama administration. Opening the door -- even briefly -- to the idea of U.S. troops in Syria provided fodder to many on the liberal left who are worried that this situation could turn into another Iraq. And, Kerry's "unbelievably small" comment today fuels the argument made by many conservative Republicans that the president wants to use military force against Syria just to say that he made good on his promise to do so.

What gives?

That depends on whom you ask.

Some people attribute Kerry's stumbles to a well-documented pattern of the former Massachusetts senator for making a verbal gaffe or two. Remember Lambert Field? Or Swiss cheese on his cheesesteak? "You may recall this is not new for him to mess up when tired," said one senior Democratic operative. Kerry's latest gaffes could then simply be a reflection of his being worn down from a steady stream of travel and TV appearances to sell the administration's policies. (Of course, those sorts of slip-ups during a campaign are far more minor -- and with significantly less impact -- than his recent comments on Syria.)

Others suggest that the very fine line the Obama administration is trying to walk puts Kerry in a very difficult position. On the one hand, the president is insisting that the use of chemical weapons in Syria amounts to a moral crisis for the world that must be answered for fear of major repercussions in the future. On the other, the president is trying to sell the military action as targeted and limited in hopes of winning over members of his own party who are very skeptical about voting "yes."

So, the Syria strike is both absolutely necessary and absolutely limited. That's a tough sales job for anyone -- Kerry included.  And, given his current job, Kerry has no choice but to be the front-and-center salesman on this effort.

Here's how WaPo foreign policy blogger Max Fisher put it:

Regardless of the reason(s), Kerry finds himself at the center of the growing storm over Syria without any good answers. And that's not a good place to be.