Contra Jim Manzi, I don't necessarily think that liberalism is going to take some great leap forward, electorally or in the national consciousness. But then, I don't think that this is how liberalism generally moves forward. True, the sixties represented in many ways a flowering of liberalism. But I think that moment was sui generis, and I don't think it represents the general movement of liberal growth in popularity.
Instead, I think that the culture gradually moves towards liberalism in a subtle way, which helps to create the rhetorical and media atmosphere we live in where everything is always bad for liberals and Democrats. I don't have it in me right now to make a comprehensive post about media bias, but I will say that I think that the general conservative line that the media is simply biased towards liberals and liberal policies is absurdly reductive and oversimplified. Media bias is complicated and nuanced, and has nothing resembling a simple directional vector. One sense in which liberals are most certainly not the benefits of bias is in the phenomenon where the mainstream media interprets every possible political happening, short of actual electoral victory, as being bad news for Democrats and liberals. And, of course, this fits with the conventional wisdom of at least the last decade and probably longer, of ascendant conservatism.
So why don't I frequently feel like I'm living in an era where my ideals and policy preferences are threatened? Because I think that, while conservatism and Republicans have had more high-profile victories and better pub, I think liberalism has been on the march in a less visible way. Gradually, what is considered liberal changes, so that ideas that would be viewed as leftist in the recent past have become mainstream and moderate. Much has been made of the steady march of social liberalism into the mainstream of American life, with gay rights being the most obvious and visible factor. I don't like to engage in notions of political inevitability-- the recent hysteria about illegal immigration, which became the most important issue in America and just as quickly was forgotten, helps to demonstrate that you shouldn't ever consider any particular changes inevitable.
But I find gay marriages in all or a majority of states within my lifetime to be very likely. Indeed, the gay rights agenda as a whole seems on the verge of being a non-ideologically situated movement, firmly ensconced within the political center. What that means is that, should gay marriage eventually become the law of the land, it's unlikely to be seen as a victory for liberalism. That's the sense in which moving goalposts create the impression of constant liberal weakness. (Of course, if gay marriage does become widespread-- a development consonant with my ethical and political preferences-- who cares how it looks?)
That's just one issue, of course, and this idea is subject to many exceptions. In general, though, I'm resistant to "grand narrative" notions of politics, and I think that this explains part of the reason why the project of liberalism is rarely in as bad shape as it may seem.