Realistically, it's always easier to get people united against a common threat than for a common goal. I think the membership was much more unified in the beginning because the Democrats were in power. Since the Republicans came into majority there has been a perception that the "conservatives" are now in control of the political power, and we've fallen into factious squabbling over how it's ought to be wielded. IMHO.
Very well said.
You have placed your finger right on the Democrats entire playbook. And you have placed your finger as well on the Balkanization of the GOP. The Democrats have learned that people in America today are highly preoccupied with lives that don't allow for them to even find the time for basic needs (like raising their own children, cleaning their own house or preparing their own food). What down time is left in people's lives from highly demanding jobs and a highly complicated society (with highly complicated family lives) is not liable to be reserved for educating yourself and applying yourself to policy or civics.
The Democrats are better grasping the truly tuned-out, turned-off society: Their politics are based on creating ogres and then hating them with great passion...publicly. Hate can be understood quickly, with minimum effort or time expended in understanding it. It's easy to demonize and foment hate -- it's been a classic political tactic of demogogues for millenia. For the Democrats they foment the hatred of easy marks like religious conservatives ("wanting to tell everyone else how they should live"), of the white male taxpayer ("greedy bastard, put where he is by the old boys club, sitting around in his 50th floor office telling you how to make him more money"), and of course, George Bush ("killing your sons and daughters for his own profit and that of his buddies and friends" "he's a dunce, he's stupid and he's greedy").
Hate is something that doesn't take time or energy - so for the voter with very little time and very little energy, very little interest or with a chip on their shoulder about their place in life, hate is just speaking to them in their own language.