The Republican Party — and both parties, really — have gotten more extreme in recent years. Everyone knows this.
What many people don't know is that, for the GOP, it wasn't a linear move.
As the below chart from the Pew Research Center shows, Republicans in the late 1990s and early 2000s actually appeared to move away from the far right portion of the political spectrum and toward moderation.
While 13 percent of people registered as "consistent conservatives" in 1994 and 20 percent claim that mantle today, the number fitting that description actually dipped down to 6 percent in 2004 — about one-third of where it is today.
And while 45 percent of Republicans were at least "mostly conservative" in 1994 and 53 percent fit that description today, that number dipped down to 31 percent in 2004.
Those are pretty big dips.
So what happened around 2004? Well, for starters, we're guessing a lot of it has to do with the fact that the GOP wasn't the opposition party. At the time, they were in the middle of the George W. Bush presidency and held both the House and Senate as well.
But Democrats don't show any similar differences between when they have been in power and when they haven't. Indeed, their progression toward the political extreme has been very consistent over the past 20 years. (It's also possible that the two parties simply adjust to being out of power in different ways.)
An alternate theory: While the GOP in 1994 was defined by the Republican Revolution and the Contract With America, and while today's GOP is defined in large part by the tea party, the GOP in the early 2000s had a president who was preaching the ideal of "compassionate conservatism."
The brand of conservatism in today's Republican Party would almost certainly be dismissed by the tea party as wishy-washy — code for big-government conservatism — but back then it was en vogue.
We would bet that Democrats wish there were a bigger strain of compassionate conservatism in today's GOP.