I think it's still two parties, but the guiding force behind the Republican Party is a loosely amalgamated group I like to call the Lucrescenti, or Lucrascenti depending on your spelling preference. (Second choice was The Corporatistas, but I like Lucrescenti because it sounds creepier.)

As you might expect from the name, they're all about money and the reason they gravitate toward and work out of the Republican Party is that Republican votes can be purchased much more cheaply than Democratic votes.

Whenever we wonder what motivates Republicans to do what they do, it's worth reframing the question into something like "What motivates those who run the Republicans to do what they do?" And you'll discover that the answer lies in what the Lucrescenti consider the inconvenient necessity of obtaining 51% of the vote, what with America still clutching quaintly at Democracy and all. This is done by taking advantage of the death of context and spending a little money to get groups of people whipped up over a single issue or narrow group of issues. (It is of course necessary to pretend that these issues actually matter, but not in any meaningful way.)

The ramification for Democrats is that we need to understand that the best way to put the Lucrescenti on the defensive is not to focus on one nutty Republican antic after another, but to raise the price of votes. More on that later....