Inspired by Tyler Cowen, let me offer my most generous characterization of progressivism:
Progressives are the proud heirs to a tradition of experiments in public policy that brought about significant social improvements. Its antecedents go back before the Civil War to the anti-slavery, temperance, and women's movements. They continue forward with a focus on civil rights, women's rights, birth control, public health, anti-trust, economic justice, central banking, business cycle management, and ecology. Society today is much better because of the policies that progressives promoted in these areas.
All along the way, progressives met opposition from conservatives and libertarians. Yet few would now step forward to try to reverse progressive policy successes. The arguments against civil rights legislation made by Barry Goldwater and Milton Friedman in the 1960's clearly put them on the wrong side of history as well as the wrong side of today's generally accepted morality.
We need to continue to drive government policy in the direction of social improvement. The progressive agenda on health care, energy, and income inequality will turn out to be another success story, once progressives overcome the opposition.
[Note: I continue to believe that progressivism entails this. And I believe that the current progressive agenda is going to end up working out closer to such failed past progressive ideas as Prohibition, the National Recovery Administration, and public housing projects.]