Matt Yglesias is on the money when he points out that when progressives want workers to get more money, they must implicitly want someone else to get less. Now there is a real real big exception to this point, that being the current economic slump. In a context where the economy is producing at a rate that is around 6 percent (@ $1 trillion) below its potential, then we can literally talk about a situation in which we expand the pie and there is more for everyone.
This is why the concern about waste in the stimulus was so absurd. If the issue was whether we had spending that was partially wasteful or no spending, then the answer is spending that is partially wasteful. Otherwise the resources would just sit idle (meaning more workers are unemployed) and we get to celebrate that we didn't put people to work on partially wasteful projects. (Of course less wasteful is always better than more wasteful.)
But if we envision one day being back in a world where the economy is operating near its potential, the good guys getting more means the bad guys getting less. The right eats, breathes, and sleeps with this logic. They understand that when they push down autoworkers' or school teachers' wages, there is more for them. They understand that cutting Medicare or Social Security means more for them.
If progressives want to secure more income for ordinary working types and the poor then it will have to come at the expense of someone else. I have my list (CEOs and their friends, doctors and lawyers, Wall Street financial types, bringing corporate profits back to earth would also be a good idea). Others may have a different list. But if there is no one who is going to lose out in progressive policy post-full employment, then there is no one who is going to win either.
Of course at the speed we are getting to full employment many of us won't have to worry about this problem in our working lifetime.
After reading the comments, let me make the point a bit more clearly. The right has found ways to use the market to kick our asses. Progressives should find ways to use the market to kick their asses. These ways are all over the place: opening up trade in health care, making it easier for foreign doctors and lawyers to practice in the country, make the financial sector pay the same sort of taxes as every other sector, ending too big to fail in the banking industry, etc. These are mechanisms that require the government to get out of the way (in the case of financial sector taxes -- not privileging one sector over others). If Occupy Wall Street was saying these things they were not very effective in getting their message out.