Here's Jonathan Bernstein responding to Adam Serwer on the political appeal of hopeless fights:
Generally, there are usually lots of incentives for politicians to fight hopeless fights. They get all the publicity and none of the responsibility. Hopeless court fights are great, because they promise to stretch out for years, with no obligation to put together complex legislation (which could actually harm their constituents if enacted), or deal with the consequences of a victory. [...]
Anyway, the main point here is that hopeless fights are often a politician's best friend. Especially those not especially interested in governing.
I'll only add that this is a fact understood by all sides of the question. From the beginning, it was clear that the public option -- or something like it -- was out of reach for health-care reform. Conservative and "centrist" Democrats were opposed to the measure, and without them to break a filibuster, there was no way it could happen. Even still, prominent Democrats -- including the president of the United States -- continued to speak in favor of a public option, and activists continued to fight for its inclusion. The fight was doomed, but it was useful; in addition to the publicity, advocates had a constituency for further reform, and politicians could build credibility with activists and particular groups. Even for those interested in governing, hopeless fights can be a useful tool.
