"legal under certain circumstances" is obviously synonymous with "illegal under certain circumstances"

Uh, excuse me? No, if 51% think it should be legal u.c.c., then 49% think it EITHER should be illegal u.c.c., or perhaps they don't have an opinion... there might even be other categories. They are definitely NOT synonymous.

A false dichotomy is created when the anti-abortion stance is labelled as 'pro-life' since it creates the unavailable converse, anti-life, which is then labelled 'pro-choice'. To take the obvious example, preventing the abortion of an anencephalic foetus is not a pro-life choice because there is no viable life to be preserved. To then ask the questions differently by referring directly to abortion and compare the answers with the previous formulations is not meaningful. One should not, therefore, be surprised if the results appear paradoxical when like is not compared with like.

It's not necessarily evidence of conflicting views. Personally, I disagree with abortion, but I think it is a woman's right to choose and it should be available. I'm not a woman, so I'm never going to be put in the position of having to decide to terminate a pregnancy for whatever reason. Therefore I am allowed to disagree with abortion at the same time as recognising that it is something which, for many reasons, has to be available. Rather than a conflicting approach, it is a pragmatic view.

Friends of mine have had abortions and I have happily talked it over with them when they were having to make the decision. At no point did I try to influence their thinking or try to get them to change their mind - what was right for them as a woman in their individual situation was what was important. Perhaps the poll is evidence that people, while objecting in principle, take a more nuanced view than they are being given credit for.