Democrats try to figure out how to read polls like Republicans ...

The key insight:

When Republicans segment voters into groups, they typically use the "most important issue" questions to do it, whereas Democrats typically use demographics, speculating, for instance, on how married women or African Americans will vote and then tailoring their campaign strategies to the various groups. While demographics offer insights into who is thinking what, it is much more useful to be able to identify the single issue that will determine someone's vote.

Of course, you also have to have appealing positions on those issues. Maybe the Democrats will figure that one out next time around.