Successful big victories over Isis (IE Mosul, Aleppo, raqqa) as election day nears would help hillary. The problem is if they made a conscious decision to hold off doing so for that specific purpose when it could have been done earlier and saved lives. You cannot play with life and death decisions for political advantage... It's completely immoral & unethical, but from what we now about the character of Obama & Hillary (or lack of; Benghazi is one example) it is completely possible that they are doing now what they could have done before and saved a lot more lives.
"CNN) — Defense Secretary Ash Carter said Wednesday it will be only a matter of weeks before the US and its allies are ready to drive ISIS from Raqqa, its symbolic capital in Syria...."
http://edition.cnn.com/2016/10/26/politics/defense-secretary-ash-carter-raqqa/index.html