#4: US Political Party Affiliation Trends

Last time I talked about my desire to show data better. Pasting images is fine, but I’d like to explore ways to put the data into the document itself. But until I can figure that out, please enjoy this pasted image.

US Political Party Affiliation, 1960–2015. Blue is Democratic, Red is Republican

The Story In the Data

We see a few interesting things here. First, Democrats hold a consistent edge in party affiliation. There were more Republicans in 1995, but that turned out to be a blip in the data. Second, Democrats have steadily grown their numbers since 1990, and Republicans went up then went down, landing in approximately the same place. Finally, there’s evidence that Republicans are growing their numbers and Democrats are seeing a slowdown as of 2015.

Methodology and Important Nuance

I should be very clear about how I got these numbers, because slight tweaks in the formula could change the results. For each year, I took the population of America and carved out the population of people that identified with a particular party. Let’s take 1995 for example:

US Population in 1995: 266,278,000
Percentage of citizens affiliated with GOP: 31%
Percentage of citizens affiliated with Dems: 30%
Estimated number of Republicans in 1995: 82,546,180 (266m * .31)
Estimated number of Democrats in 1995: 79,883,400 (266m * .30)

This is an imperfect model. There are plenty of people in the census that can’t vote, for example. But even if the raw numbers aren’t accurate, the general ratio between Republican and Democrat is.

Another big detail is I didn’t count “leaning” voters. One of the most notable trends about party affiliation is that there are more independents than either Democrats or Republicans. To deal with this, pollsters ask what side people lean towards, then include that in the data. But I wanted to get a sense of the proud bases of either party.

Foolish Speculation

Actual data scientists would stop there. They like to use terms like “inconclusive” and they stress not to read too much into data or try to bend it to fit a pre-conceived narrative. And they’re right. But stopping there isn’t really my strong suit. I’d like to speculate further.

2016 is shaping up to be a landmark year in US politics. The odds are in Hillary Clinton’s favor to become president and for Democrats to take the Senate. This means the Supreme Court will swing left. If that happens, we’ll see the power balance swing like this:

House stays with Republicans
White House stays with Democrats
Senate switches to Democrats
Supreme Court switches to Democrats

That’s a lot of power for Democrats. They won’t fully control congress, but they’ll be playing with a much stronger hand than they enjoy today. And this will all happen before a backdrop of a Republican implosion, which is a huge wild card.

Donald Trump has transformed the party during this election. If he wins the White House, the GOP will have to go along with his proposals because they’ll have no choice. But if he loses, I predict a civil war of ideas. Half the party will say they should have been more Trump-like. Half the party will say they need to run away from Trump’s policies. And that process will take time. Meanwhile, the Democrats are going to schedule lots of votes on popular proposals like expanded parental leave and reducing big money in politics. The Democrats will be united, the GOP will be in disarray.

So then what? I’m not sure. Democrats could overreach and throw more people into the GOP’s orbit as a result. But I think the more likely direction is a three party system when the GOP splits. The pro-business traditional conservatives will represent about 25% of voters, the Trump-inspired voters will represent about 25% of the voters, and the Democrats will represent the remaining 50% of voters.

Personally, I expect to see Democratic numbers grow or plateau and I expect to see the GOP go down significantly in the next two years. We’ll see!