The following is a short (6 minute) video by Robert Reich. Reich is the former Secretary of Labor under President Clinton. He may be optimistic,  but he always brings up great points:

Labor was once the very backbone of the Democratic Party. They should still be. The Democratic Party is certainly the only major party in the US that works for labor issues.

Why a worker would ever vote for a Republican is a mystery. Republicans use their power to decimate workers.

In a similar vein, why would a small business person vote for a Republican when Republican policy is geared to helping the giant businesses crush small business?