They must achieve unusually high turnout to win?
Don't think so.
Whatever you do, don't trouble yourself with the data. You might end up as a Republican. That would be awful.
There was nothing unusually high about turnout during the elections of the past 10 years where Democrats have won.
And no, not being abysmally low doesn't quantify as unusually high. It might be surprising, but there are still people out there who will vote for both Democrats and Republicans based on who they feel is the best choice. People felt that way in 2014 and 2010, and if there's a not exceedingly popular Republican elected in 2016, they'll vote opposite how they did in 2014.