On yesterday's Lieberman diary of the day,
http://www.dailykos.com/story/2005/2/12/17112/3162 besides the usual pro-Lieberman arguments, it was stated that symbolic votes, i.e., votes that have no influence on the actual outcome, are essentially irrelevant. (This was in the discussion of Lieberman's pro-Gonzales vote.)
I didn't respond at the time, being too busy objecting to the charge that being anti-Lieberman = anti-semitism, but I did spend some time last night thinking about it, and I decided this argument is nuts.
Of course a symbolic vote has not only symbolic value but actual value.
A positive vote helps define not only the voter, but his beliefs and his party. It shows the faithful that their leaders are keeping the faith. It brings comfort to the afflicted (sorry, it's Sunday). It reminds the rest of the world that all Americans are not pro-torture (I'm using the Lieberman-Gonzales example still). It helps sway those who might be undecided on the issue. It would, most pragmatically, help with fundraising.
Alternatively, a negative vote makes it easier for people to believe that Democrats have no values, thereby probably losing more voters to the Republicans, who at least seem to believe in something, even if it's wrong. A negative vote sows dissension among the ranks, raises the level of cynicism about elected officials. It raises the level of cynicism abroad and among Muslims about Americans plans for Iraq. It also makes it a lot more likely that disaffected Connecticut Democrats will try very hard to find a strong primary challenger.
Some of these consequences of voting are psychological and subjective, but that doesn't mean they aren't real. So, help me define here what makes it worthwhile to cast a purely "symbolic" vote. For example, most of us thought it wasn't absolutely necessary to cast a no vote on Rice, but that it was much more important on Gonzales. What about the anti-gay marriage amendments? What about the IWR?
Basically, I'm asking, what are the parameters that make it important to cast a given vote, even if it won't change the outcome of the voting?