From Dictionary.com
Pragmatism noun
1.character or conduct that emphasizes practicality.
In other words, doing what works.
ALL the great progressive presidents were pragmatists, notably, in the 20th century, FDR and LBJ. In the 19th, certainly Lincoln was.
FDR tried one thing after another. He didn't come into office with a strong sense of what would work, he just had a strong sense of what would NOT work: Everything that had been tried.
LBJ twisted arms and made deals, and then, looking at it pragmatically, he bargained for civil rights by giving the south to the Republican party; in his words "We will lose the south for a generation".
At lower levels, other elected politicians are pragmatists too; they have to be. The ones who are not don't get re-elected. Ronald Dellums once said that he was in Congress to "do his thing" and he kept getting re-elected because "his thing" corresponded with the "thing" of his constituents.
Or, looking at it another way, why is Ben Nelson like Ben Nelson? Because not a lot of his constituents want him to be different. These are the same folk who elect Johanns to the Senate, who gave McCain 57% and who gave Bush 66%. Sure, someone could run as a progressive in Nebraska. That wouldn't be pragmatic. It also wouldn't win.
You can be pragmatic, or you can lose.
If you want to move politicians to the left, you have to move people to the left. THAT is why OWS so terrifies the Republicans. Are they scared of the people actually in the parks? Not really. Great as the movement is, only a tiny fraction of people are camping in parks. Maybe, all over the USA, MAYBE 100,000. Out of 300 million. No, what scares them is that by putting issues in the spotlight, the OWS movement will move the masses of people to the left; will wake them up, energize them, make them aware of their power.
Supposedly, when Lincoln met Harriet Beecher Stowe, he said "so, this is the little lady who made this big war". The story seems to be apocryphal, but the message is clear. Uncle Toms Cabin was an immensely popular book that made a lot of people feel sympathy for the slaves - people who had not really felt such sympathy before.
The people lead.
The politicians follow.
[[UPDATE thanks for the rec list. I have to go out for a few hours. Back later]]