I do not see any reason why a moderately progressive political party, such as Democrats, cannot pursue most if not all of them - provided they see enough popular support behind them. I hear a story about FDR replying to a lobby group "You convinced me about your proposal. Now make me implement it." I am positive that if there is enough popular support for a cause, Democrats will pursue it. If they do not pay too much attention to some of the left's positions, it is because the left is weak.
As far as Doug's idea of worker's control of the means production - that is a very tricky one. Technically speaking, publicly traded corporations ARE controlled by their employees rather than owners - since CEO is an employee. So the real questions are "What kind of workers? And "How?" Is someone with 20-year seniority and experience in the company going to have the same say as a novice who started yesterday? What is an institutional mechanism of exercising worker's control of the company? If not stock ownership (now democratically available to anyone), then what? Direct democracy is yet to work in any more complex social system, and representative democracy has all the shortfalls of the current system.
Wojtek