I have often considered a key difference between Democrats and Republicans the range of opinion expressed in the respective camps. The D's tend to have a whole host of opinions on matters of foreign policy, social issues, strategy, you name it. This can be counterproductive for obvious reasons, but I figured it just meant they were smarter and thought things through. Meanwhile I thought the GOP were all taking marching orders and have zero difference of opinion on anything.
The Republican Primary has changed my thinking on this matter significantly. Most of us are familiar with the universals within GOP talking points: no taxes (on rich people) government is "the problem" and a scary disdain for the separation of church and state. However, I think that the coalition between religious fundamentalists, greedy business types, wacky libertarians, and disgruntled blue collar workers is ripe for collapse.
The PTB do a great job of getting factions within the Democratic Party and even progressives outside of it to work against their common interests. The most famous example I can think of is Nixon's Southern Strategy. The game plan was to stoke the fears and racism of southern whites (reliable Democratic voters for decades) and get them to vote for Republicans after the victories of the Civil Rights movement.
My point is not that the Dems should have been more racist (probably what some Blue Dog Democrats would conclude today), but that Nixon and his cronies did a remarkable job of getting the Democrats to work against each other.
It goes without saying Democrats are often their own worst enemies, whether you think they are actively on the same team as the Republicans or that they are just weak/ineffectual. That being said I do think things in this country would be remarkably better with the Republican coalition split up.
One example of this split is Mitt Romney Republicans and Michele Bachmann Republicans. The Romney-type are wealthy, establishment Republicans, some of whom even "get it" on social issues (even a blind squirrel gets a nut sometimes). However, most are so filled with greed that they could not care less about climate change, workers rights, or economic populism. They kind of hate stuff that helps regular people without making them a quick buck (see Social Security) but don't rationalize it with some bizzare reading of Ayn Rand, instead it's framed as technocratic "reform".
In the other corner there are people perhaps best typified by Michele Bachmann. These are the full-blown wing-nuts, who think evolution and climate change are schemes of evil scientists. They are birthers, biblical literalists, and anything that government can do to help is "unconstitutional". Incredibly many of these people are not in the top 1% in terms of wealth, but reliably vote Republican only to get screwed on economic issues.
Obviously there is overlap between these 'factions', but I can't believe these people are in the same party. If Democrats could consistently play these groups against one another, I believe the GOP Convention in 2012 could look like the Democratic Convention of 1968. But I'm not holding my breath.