Someone is going to be angered and feel alienated by what decision he makes, by the outcome, and symbolic paeans to inclusion are unlikely to soothe that. Those who are eager to escape confrontation, divisions, and angry disputes can probably do so only by renouncing any actual political principles, and are probably best advised to avoid politics altogether. Because of the very nature of politics -- to say nothing of the nature of the contemporary American Right -- politics is highly unlikely to exist without angry, often ugly, conflicts of that sort.
Reasonable arguments can certainly be advanced in defense of the virtues of Obama's post-partisan theory of politics. But it's simply unreasonable to depict any of it as new. It's exactly what Democrats have been clinging to, desperately and mostly with futility, for two decades at least. Trans-partisan harmony comes only when Democrats agree to sacrifice what they claim their beliefs are and to show contempt for the "Left," and even then, the "harmony" is fleeting, insatiably greedy and inch-deep. It's certainly possible things will be different this time around, but in the absence of actual evidence, it's really hard to understand why so many people have become so intractably convinced that it will be.
If fighting makes you stressed and disagreement makes you uneasy, stay out of politics (or the military). You don't want them and they don't want you. Find some puppies and children to rescue instead; it'll be a better use of your abilities and temperment.
Democrats can be authoritarian too. When someone says that Obama's choices shouldn't be questioned because he knows what he's doing, that's authoritarianism. Authoritarians will sell you down the river to feel like part of a group, safe and wanted.
There is no sudden disappointment in Obama; there are people who knew what he would do because they read and listened to him speak, and there are the perpetually surprised authoritarians who thought that they and their leaders had the same goals and aspirations, just because they were in the same group. Obama is a religious authoritarian and he doesn't care about gay rights. This is not a surprise, and anyone who is shocked and angered was fooling himself before, and should be ignored.
Added: If he actually passes equality for gays, I will eat my words.