The Democratic Party platform is a very different document this year than in 2008. It’s far more interested in celebrating what the Democrats see as the accomplishments of the Barack Obama presidency than it is in advocating new proposals. That’s a reasonable choice.

What’s fascinating are the areas in which specific proposals and promises remain, and those where they are gone. The section on abortion remains as strong as it was in 2012. There’s a well-publicized new plank in support of marriage equality, along with a pledge to support the pro-gay rights Employment Non- Discrimination Act.

In other areas…not so much. Democrats retreated, at least rhetorically, on climate and energy; They also retreated on civil liberties. On health care, there’s some retreating, too: the platform is mainly concerned with touting the popular bits of the Affordable Care Act, not with specifying what Democrats might want to do in the future; indeed, the public option would appear to be toast.

In part, all this reflects a natural tension on the platform, and on public policy commitments during the campaign, between the party and the candidate, who sometimes have different interests. For politicians (particularly presidential candidates), the strong incentive is to take as few policy positions as possible. That leaves a candidate flexibility to use position-taking tactically throughout campaign, and more flexibility once in office.

But for the party collectively, and for activists and groups within the party, policy specifics are valuable: they place constraints on their own politicians. In the platform we can see hints about which groups are strong and which are weak within the party. Indeed, there’s a lesson here for activists and organized groups: liberals tend to get what they want only when they fight effectively for it.

Pro-gay marriage groups relentlessly pressured the president throughout his term and refused to drop the marriage issue, even when they scored other victory. They got what they wanted. By contrast, there simply was no comparable effort on civil liberties; on the public option, groups pushed hard during the health care battle, but after they lost, they basically dropped the fight. They have not gotten what they wanted.

So the lesson of the platform is this: if you fight within the party, it’s certainly possible to win; if you don’t fight, you’ll certainly lose.