Some folks in comments below are, apparently without reading the post, reciting lines about the perfect being the enemy of the good and ideological tests. So let me make this clear: progressives taking a stand on the public option are letting the good be the enemy of the awful, and our only ideological test is the the belief that legislation should not make people worse off than they already are. At the beginning of the summer, it never occurred to me that the Democrats would consider legislation that actually makes people worse off than they already are, but now I'm looking at the Baucus plan, which would put a lot of people in a situation where they have to cut into rent and food and childcare money to pay for mandatory insurance, and I'm seeing people having to give up jobs or homes in order to meet these regulations, and I'm seeing people made worse off than they already are. There is a strong potential that people will have to pay ever-escalating health insurance costs with no ability to buy into a public option, and no way to opt out, and they will have to give up their homes to cover it, or lose their jobs because they cut into childcare money, or lose their health because they stopped eating right in order to pay for this. To make it worse, with mild fines for refusing care to sick people, insurance companies will be able to budget it that in and still refuse care, so the improvement in actual access to health care will be minor. Result: people will be worse off than they already are.
Is that clear enough? Our ideological test is the common sense one: It's immoral and stupid to make people worse off than they already are.