The chart above is from a recent survey done by the Pew Research Center. It was done between July 31st and August 12th of a national sample of 4,000 adults, and has a margin of error of 2.6 points.
I think it shows just one more reason for Democrats to be encouraged in this election year. It shows the difference between Democrats and Republicans in political activism in four areas -- contacting an elected official, contributing money to a candidate or party, attending a political rally, or working/volunteering for a candidate or party.
While there are differences in the age groups, one thing is consistent -- Democrats are more politically active this year than Republicans. Why is that important? Because politically active people WILL VOTE (and they are more likely to encourage others to vote).
This does not insure a Democratic victory in the November election, but it does make it much more likely.