The most important factors in November will be the perceived health of the economy (good enough to elect Mrs. Clinton), President Obama's approval ratings (which seemed to rise just around the time that Trump and Hillary became the apparent nominees -- go figure!) and whether or not there's a significant terror/national security event in the fall.
Need more reassuring? Democrats have won five of the last six popular votes, their demographics continue to improve, and they have a big advantage in the Electoral College.
Don't be too surprised if the results look a lot like the election of 2008, above, or 2012, below.