David Sirota makes a terrific point about the lack of progressives' and liberals' ideological focus in his review of America's Right Turn. I agree completely with Sirota: There is a lack of ideological focus on the left, and it has crippled our ability to implement humanistic, liberal principles in actual real-world politics. It's not my intention to contradict Sirota, but he gives us only one side of the story, and I want to talk about both sides.
While a lack of focus is definitely crippling, too much focus--or focus on the wrong things--can be just as debilitating. The most obvious example is in today's politics: The conservative movement's rigidity and fixation on its ideological principles has handed the Democratic party a majority in Congress in spite of the party's almost complete lack of any consistent, coherent ideology. One can also look at Soviet and Chinese Communism and just about any major or minor religion; certainly no one can accuse them of ideological spinelessness.
The defining feature of this sort of bad ideological rigidity is its disconnection from reality. The Republican party lost Congress not because the war in Iraq was unjust or immoral (which it was), but because they allowed their ideological principles to override their grasp of reality, botched the job, and have lost the war. The war was probably winnable (although at a moral cost which would have sickened any liberal humanist), but they didn't win it. Contrawise, the war was also entirely avoidable on even conservative principles, had the ideology not substituted for a rational assessment of reality.
I think we definitely must have greater ideological focus and discipline in the progressive, liberal movement; it is not enough to stand for only standing for nothing. Before one can compromise, one must have some definite stance from which to negotiate. On the other hand, we must also ensure (or at least stave off for as long possible) that focus and discipline does not degenerate into rigidity and delusion.
It is not possible to rigorously define how well an ideology maps to reality. It is entirely possible to make a good, rational case for the realism of any ideology right up until the moment that some catastrophe highlights the delusions and brings the movement to its knees. On the other hand I believe there are some ideological and procedural measures that can keep any movement from straying too far from reality.
The most important step is to break the "ought-is" connection. Just because something is good does not mean it is true. It was good (according to conservative ideology) that we should invade Iraq, therefore it was true that we could successfully do so. A moral stance never implies anything at all about reality. To be successful, any movement must take into account both its moral position as well as an objective, scientific view of the reality which cares nothing at all about our moral judgments.
For a movement to be disciplined and focused entails that it restrict some forms of internal criticism; to maintain flexibility and a connection to reality, however, entails that it must allow some other forms of internal criticism. I don't think it's possible to draw this line with razor-sharp precision, but I think some guidelines can help. Rationality demands we must break the ought-is connection, which suggests where to at least roughly draw the line: What is good and bad is an essential feature of an ideology; if you do not subscribe to the moral dimension of the ideology, you are simply not entitled to criticize it internally (one can, of course, externally criticize the moral dimension of any ideology). On the other hand, criticism of the ideology's connection to reality must always be internally permitted.
(The gray area, of course, lies in that it is not always possible to determine whether some internal criticism is really a criticism of the morality or of its implementation.)
Any moral ideology must be meaningful in reality: If an ideology defines something as good, we also need a way of objectively telling whether that good is or is not actually appearing in reality. Any ideology which does not have an objective way of measuring its own implementation is nothing more than metaphysical mumbo-jumbo. An internal critical process is necessary, but the practical failure of of Marxism, which elevates vacuous dialectic to a religious principle, shows that just any old kind of internal criticism is not sufficient.
An internal critical process must be based upon some connection to reality. The scientific community is the most successful institution ever devised, and its success is due to its monomaniacal focus on reality-based internal criticism, the insistence (in principle at least) that internal criticism be exclusively based on experiments rather than consistency with some revealed authority or based simply on how loudly one can shout.
Probably the most important pitfall for any movement to avoid is to "root for the shirts". Again, the present difficulties of the conservative movement can be traced in no small part to the reliance on the Republican party by the conservative movement. Despite the early separation between conservatism and the Republican party, years of successful cooperation appears to have led to a degree of complacency. Conservatives stopped voting for Republicans because they were conservative and started voting for them because they were Republicans. In response, Republicans stopped actually implementing conservative principles and simply degenerated into the worst kind of self-serving corruption.
The preceding is all very abstract, so let me provide a more concrete example in my own view of progressive liberalism.
The moral dimension of liberalism is Humanism: what is good is individuals' human happiness; what is bad is individuals' human suffering. This moral view stands in contrast to the conservative (and especially Libertarian) view that society should be a particular way (e.g. laissez-faire capitalism, Christian sex-negativity and hierarchal authoritarianism), that certain societal mores are intrinsically good. If these mores result in human happiness, that's a bonus, of course, but if they result in suffering, that's just too bad.
While happiness and suffering are the epitome of subjectivity, it is trivially easy to objectively determine whether someone is happy or suffering: You simply ask him. It is therefore possible (at least in principle) to measure whether some practical agenda is has a humanistic, liberal effect in reality: Ask the people. Of course, it is decidedly not trivial to determine in advance whether some proposed policy will or will not have a humanistic effect. Nor is it trivial to determine how precisely to measure happiness or suffering on a statistical scale, or which particular measures we should concentrate on optimizing.
The moral dimension of liberal humanism is not internally questionable. Either you agree, and you're a humanist, or you disagree and you're not a humanist. It's certainly possible to externally criticize the moral dimension of humanism, but the fact that one merely brings up a moral criticism makes it an external criticism. Contrawise, pointing out that someone doesn't hold to the moral dimension, the essential moral vision, is always legitimate internal criticism.
On the other hand, there is debate about how to actually promote human happiness, how to prevent human suffering; in general about how it is most effective to implement humanist moral values in society. Such debate, such questioning is always legitimate as internal criticism, no matter who offers the question and no matter whom is questioned.
The Democratic party appears, at least at this point, to be the best means to implement a liberal, humanistic moral vision in society. But we must not worship the party itself over and above our moral vision. Democratic politicians are, first of all, politicians: It is their job to do whatever it takes to be elected. They will actually act according to a moral vision if and only if that moral vision is necessary to be elected, if and only if each individual citizen votes for any politician, Democratic or Republican, only if the politician subscribes to the citizen's moral vision and is accountable for how well its been implemented.
It's not enough for the Democratic party to be not as bad as the Republicans. It's not enough that they are not as corrupt, not as stupid, not as indifferent to happiness and suffering. If a Democrat is not as bad as her Republican opponent, I might cast my vote in her column, but I'm voting against, not for. And I might well simply vote for a marginal candidate who actively subscribes to my own moral vision (as I did in 2000*) and too bad if the worst candidate wins.
If progressives have and can enunciate a clear moral vision, maintain internal focus and discipline adhering to that moral vision, maintain a reality-based internal debate about the effectiveness in implementing that moral vision, and avoid conflating the movement with the party or its leaders, we can not only steal a page from the Republican play book, but do them one better and actually get things done in reality.
*I like Al Gore, I like him a lot. But he ran (ideologically) in 2000 not as a progressive or a liberal but rather as a moderate conservative (basically Clinton without the charm). And I'll be damned if I ever vote for Lieberman even for dog catcher.