The following discussion is closed. Please do not modify it. Subsequent comments should be made in a new section.A summary of the conclusions reached follows.
Thank you to Chaos5023 for compiling the chart on the talk page. Unfortunately, I was not able to use it. I found that the chart gave different valuing systems for oppose and supports (I understand the point of a super-majority, but I have reservations about this method). Supports were given three options with different weight (endorse, support, strong support) while opposition was only given a single option (oppose). Therefore, a strong support would be able to nullify three opposes. (0+0+0+4 = 4/4 = 1 (neutral)). However, the chart isn't necessary to see there is very strong support for both premises and the conclusion.
As far as titles go, I found several arguments in this discussion that I'll address. The two I found most convincing is that the topic as it stands today is US centric. It seems that in the international world, the issue of pro-life centers more on the death penalty. Also, I found and see consensus that right-to-life is too broad a subject to cover Abortion. The third recurring topic was that "Anti-rights" anything is biased. I don't see any support for this in policy. WP:NPOV does not say to avoid anything that could be irrationally or inexhaustibly be conceived as a point of view. In fact, WP:POVTITLE addresses this: "When the subject of an article is referred to mainly by a single common name, as evidenced through usage in a significant majority of English-language reliable sources, Wikipedia generally follows the sources and uses that name as its article title." This comment by Lawrence King is exactly my point. No matter how much of an attempt is made to be neutral, someone will find offense. An argument would be better supported if there were sources that argued that the use of this phrase is point of view.
According to the discussion, then, the best arguments made are that the title that meets WP:Article titles (titles that are best supported by the sources) and are US central and are clear in their scope should be the preferred titles. This conclusion is supported by Chaos5023's table. In the table, the two options that have the most support agree with this conclusion.
So then it comes down to a matter of preference. The sources support both pro-life/pro-choice and abortion-rights/anti-abortion. The tough question for me is: how can I determine a preference without it being my preference? The easy answer for me is, I don't have a preference. But how does everyone else know that? I have to determine a definitive way to find consensus on this matter. And consensus is needed because this argument has gone on for far too long. Both titles are supported by sources. On the one hand, pro-life/pro-choice would not be understandable outside of the United States for someone unfamiliar with the debate. On the other hand, when popular/media sources show equal use of both titles, then it seems logical to concede to scholarly sources per WP:Common names. Found in WP:UNC, I looked at the discussions that led to "Ambiguous or inaccurate names for the article subject, as determined in reliable sources, are often avoided even though they may be more frequently used by reliable sources." I looked at this discussion and this one and it seems that there is strong consensus that titles held by scholarly sources are preferred for ambiguous or inaccurate titles. The scientific sources seem to support pro-life/pro-choice despite that they would appear on the surface to us to be the ambiguous option. But who are we to judge in the face of scholars?
So I find consensus and policy support for premise 1, premise 2, the conclusion, and title option 2.