Knowing a little bit about polling, I can tell you straight off that your question doesn't work as a polling question. Pollsters know that you can get different results by re-wording the question, so for accurate polling you need straight forward questions. Your question isn't very straight forward.
roughly what proportion of Pro Abortion/Pro Choice people believe that
abortion should be permissible, even if fetuses/embryos are people?
For example, and I mention this purely to indicate the problem with poling. If you ask people the following:
"does government spend too much money" question will get "yes" 80% of the time.
But get into details. But get into details, should we cut money to schools, close firehouses, close hospitals, cut money for cancer research, cut money to NASA and stop the plan to go back to the moon, should we cut Medicare and Social Security and 80% of the people will be against most of that.
Basically, 60% of the people end up against what they say they are for when the question is asked from the other side. That's one problem with polling.
In addition, looking for percentages is problematic when re-wording the question changes the percentage.
And you complicate things further when you say "the person" begins at conception. The more common way that question is asked is "does life begin at conception" and that polls pretty close to 50/50.
Should we be surprised that the Christian site gets 5% higher than the news site? Probably not. There are ways to target an audience and get different results and I'm happy to split the difference and say the number is about 50/50 on whether life beginning at conception. I'm pro choice by the way and I believe life begins at conception.
"Person begins" is a little more vague. Ask people at what age does a person begin and you'll probably get a range of answers. Your question ignores that range of answers and that's bad polling. The 47% link above says that 62% believe life has begun within the first 3 months. No mention of personhood though.
In a sense, your comment does a better job of asking the question than your question does, when you wrote:
I'm definitely thinking about the ethical concept. Liberal democracy
is founded on the moral idea that there is such a thing as a person
deserving of some degree of freedom and protection. We define humans
as people regardless of skin color. We define plants and animals as
not people. I don't quite understand how something can be amorphously
quasi-person, which might be my problem
Most people would agree with a lot of this. People, for example, can get arrested or fined for abusing animals. It's legal to kill a mouse in your apt if you don't want mice, but put a video online of killing a mouse for fun and you can (and people have) faced legal trouble for that. The law is, in many ways, designed to be considerate of others, and our ethics is obviously in that direction as well. Compassion for the fetus is a real and valid ethical argument, and I don't mean to compare the fetus to an animal, I mention animal cruelty as an example only.
But the legal abortion question gets tricky because rights for the fetus takes rights away from the child bearer and that's a legal quandary. When the question was brought to the supreme court on whether a woman should have the right to choose, the supreme court said yes, a woman should have the right to choose. (Roe Vs. Wade). Ironically, Norma McCorvey, the woman who used the pseudonym Jane Roe, later regretted her decision. It's by no means an easy decision. Nobody should say otherwise. There is legal validity to the rights of the woman as well. It's ignorant to suggest otherwise and the two rights are in conflict and there's no way around that.
The answer to that conflict might be easy for you, but I've known women who've had abortions. It's been a difficult choice for them, often met with sadness and regret. Even people who are pro life, when faced with a pregnancy they didn't feel able to handle, have, more often than you'd think, opted for abortion. It's interesting to see how different it is when it happens to them and I have seen this play out. Pro life women often do see it as a choice when faced with unwanted pregnancy and some of them do choose abortion.
Questions like can I handle this or not? The physical burden, the emotional burden, can I raise this child, will I have to give him up for adoption do come up and they aren't easy. Whether it's ethical to require a woman, by law, to have their child is worth asking, and that's what the pro choice movement is about. The right to choose. Many feel that choice is natural right.
The days of back alley abortions and coat hangers, because doctors could lose their license wasn't the high-ground of ethics either. There is an undeniable ethical morality to pro-choice too. That shouldn't be hard to see.
So, back to your question as you wrote it:
In the United States, roughly what proportion of Pro Abortion/Pro
Choice people believe that abortion should be permissible, even if
fetuses/embryos are people? If actual statistics are difficult or
impossible to come by,
This is two questions asked as one. You've just written the 2nd question into an assumption, but no good poll would ask a question that way. Polls need to be as simple and straight forward as possible. Too long or wordy or assumption based and you run into manipulated polling results. This article explains that, though you have to sign-in to read it.
"Even if fetuses/embryos are people" is both scientifically ambiguous and legally false. 10%-20% of embryo's spontaneously abort. It seems, to my logical mind, little different if it's spontaneous or done by early surgery, IUD or pill very early in the pregnancy.
To ask your question, you'd need to make it two questions, ask first "when does the person begin" - at conception and offer, yes, no or probably add a not sure option.
Then ask, are you pro life or choice? (Yes/no), and you'd get 6 sets of answers.
Yes, a person begins at conception / Pro life.
Yes, a person begins at conception / Pro Choice
No, a person doesn't begin at conception / pro life
No, a person doesn't begin at conception / pro choice
Not sure when humanity begins / pro life
Not sure where humanity begins / pro choice.
I don't believe you'll find results to your question because I've never heard it asked. The question "does life begin" and "does a person begin" could change the output and it's far more common to ask "when does life begin".
But knowing how polarized people are, you're likely to find a sizable block in the "person begins at conception" and "Pro life" in one corner and "Person doesn't begin at conception and pro choice" in the other corner - the two corners staring angrily at each other . . . with much smaller numbers in the other 4 buckets. (Bucket is the correct term).
6 sets of combinations may seem overly complicated, but that's the honest polling approach to your question.
When you say this:
rough majority of politicians or activists fall.
I think we know where activists land, because activists tend to be unsubtle and outspoken about what they believe. But do you mean pro choice or pro life activists?
When you say politicians, do you mean pro choice politicians or pro life politicians? Generally (but not universally) democrats for the former, republicans for the latter.
Politicians will often speak to their audience and work for their constituency. If you want to know what most politicians really think, they often keep those cards close to their chest. We can see the bills they support, but not what's in their hearts and minds.
Donald Trump for example was very pro choice, but he knew he'd have no chance of wining the republican party as a pro choice candidate, so he ran as pro life as soon as he got into politics, despite being "strongly pro choice" just a few years earlier.
Finally, I want to add, Trump, who I'm not a fan of, expressed what I expressed in my comment above. He hates abortion, but he's pro choice. Nobody is pro abortion. People are pro choice. You writing the words pro abortion proves that you don't understand the other side at all.
That was probably longer than I'd meant it to be.