What would left-wing propaganda even be?

Teddy Roosevelt's New Nationalism, which is without racial ideology, xenophobia, or jingoism. When Progressivism fell out of favour, we leftists lost our gift of the tongue to tell why we fulfill the philosophical promises of our founding, and embody healthy patriotism better than our opponents. Our propaganda does not have to be lies, nor predicate on fools, it can speak to the power of our beliefs. There is nothing more powerful than the realization that our social contract calls for a better tomorrow in perpetuity, an eternal march toward enlightenment; the pursuit of happiness.