Because Republicans have decided to abstain from any actual debate with Democrats since Obama took office, preferring the Take Their Ball And Leave method of governing, Democrats have basically been stuck debating one another; with the key issue being whether compromise is a necessary evil to getting what we want or a deterrent which prevents us from getting what we want.
And during this debate, I began using the terms "liberal" and "progressive" to differentiate between the two sides, as a sort of shorthand of letting readers know who I'm talking about. And I recently had a commenter at Washington Monthly correct me on that, as she felt that there was nothing "progressive" about the uncompromising progressives, and would prefer to keep that term for ourselves. So I outlined my definition of these two terms, in order to better clarify how it is I use them, and thought it might be helpful to give those defintions here.
In my thinking, liberals are people who get things done, while progressives are people who shout that nothing's getting done. FDR and JFK being prototypical liberals who are best known for the things they did in office, while progressives can range from professional politicians like Dennis Kucinich, to professional protesters like Ralph Nader; neither of whom are known for much beyond shouting about how more needs to be done This isn't strictly an ideological test, as liberals can be further to the left than progressives; but merely about their willingness to compromise in order to get things done.
And both sides are needed, as progressives help push the agenda when we're out of power, while liberals implement the agenda while in power. The only problem is when we get power and the progressives start shouting at us too; which is to be expected, as that's all they really know how to do. It's their equivalent of a liberal setting up a thinktank when out of power, which are usually as inoffensive as they are ineffective.
And you can tell which side you're on based upon your compromise-to-shout ratio. Anything above 100 and you're a centrist. Anything below .01 and you're Ralph Nader. Most of us are somewhere in between. And in our current debate, the litmus test would be Obama's healthcare plan. If you think it's a necessary compromise that's better than nothing, you're a liberal. And if you think it's a Republican trick to get us to subsidize insurance companies and worse than doing nothing, you're a progressive. It all comes down to your willingness to accept compromise and acknowledge when something is better than nothing.
And of course, it should be stressed that liberals do not believe that all compromise is good, though they'll be hardpressed to convince any progressive of that. Likewise, liberals mock progressives for having a really lousy track record of getting anything done, as they're more interested in symbolic votes and principles than in actually doing things. And if you'd prefer your congressman to vote with Republicans in order to teach Democrats not to compromise, you're a progressive.