This reddit thread (which provided a lot of the original content for this post) really struck me as useful, especially for a highly politicized topic where people do a lot more emoting than thinking. The above graphs are the abortion rates per 1,000 babies born during the five most recent presidential tenures (left). The right graph shows the relative changes throughout the presidential terms. 

​The information is readily available from the CDC. The early days data is a bit dodgy, probably because it wasn't so legal/widely performed and there was more stigma. Anyway, I thought looking at, you know, real data might be an interesting way of approaching such a hot-button topic.  

#1: Wow, that's a high rate of abortion!

The left-hand chart can be read as the percentage of pregnancies (at least those resulting in live births) that were terminated by abortions. It's an interesting way of counting abortions - 200 abortions per 1,000 live births would mean that about one in six pregnancies are aborted. This likely overstates the frequency of abortion, since other babies would have been stillborn (or, more commonly auto-aborted before the mother even knows she's pregnant). How much, I dunno, but it's still close enough to discuss the numbers in a general sense. Shift the decimal one place to the right and you have a very rough idea of the percentage of pregnancies that ended in that procedure. Using this back-of-the-napkin approach, the data says that abortions peaked under Reagan at just north of one in four pregnancies. Wow!

Clearly the rate has dropped, but it's still really high. We're at 20% as of the most recent data. One in six pregnant women? Seems like a lot still. Personally, I would have guessed the rate was somewhere around 5-10%.

Why? Maybe they don't want kids? American fertility rates are dropping. There are definitely competitive disadvantages to having kids, both economic and social. It's a risky proposition, to be sure. One things for sure - almost all of us know someone who's had an abortion. That said, I don't think anyone's ever told me about getting one. This, combined with the data above, tell me that this is still a procedure that is very highly stigmatized.

 #2: Abortion frequency has steadily decreased in the past 35 years. More so under democrat presidents.

Interesting as well - abortion rates tended to stagnate under republican presidents who, as a group, represent the strongest ideological opposition to the procedure. Conversely, rates declined under blue presidents who were committed to providing better access and - I think - lower cost options.

There are a few unknowns - the chart doesn't note the congressional makeup. Obama dealt with a Republican congress - maybe they rammed down the abortion rate. It should be noted that the big decrease at the end of the Clinton era was the result of the CDC altering the number of areas surveyed from 52 to 47; the actual decrease was only about 2%. Interestingly, the areas removed were high abortion areas. 

Nevertheless, there's a steady trend downward through all administrations. Big question - why? Better family planning? More common sense? Health care pressures (presumably republican-initiated) that limited access to/increased the cost of abortions could have shifted priorities of people to providing better methods of birth control* (i.e., better prophylactic contraception). That would be a very interesting response to a policy not well tolerated by liberals.  

Another interesting theory is that abortion rates stay high when the economy is bad (e.g., Reaganomics and the Dubya era) and decrease when the economy is good (Clinton and Obama era). In effect, abortion is less representative of the political climate and more so of the economic outlook of the parents. I'm not the first person to posit the economic relationship between abortions and economy. The Freakonomics boys already covered the relationship between abortion rates and crime. Why should this be so different? 

Religion is also another factor that can probably be discarded. America has undergone a slow-but-steady divorce from religion (non-religious populations have more than tripled in the period covered by this chart). Despite this outflow of the life-begins-at-birth crowd, abortion rates continue to drop. I think it's safe to say the departure from Jesus et al has had little effect on the abortion rate. 

In summary, I'd wager people don't give a shit about what the president or their representative believes in. We're selfish creatures that act in our best interest. To reduce the abortion rate (and while I think we'd like the option in our back pocket, I've never met a person who wants more abortions, either personally or as a society). 

*It's a bit creepy to refer to abortion as a form of birth control, ain't it?