When Democratic National Committee Chairman Tom Perez declared Friday that “every Democrat, like every American, should support a woman’s right to make her own choices about her body and her health,” he instantaneously stirred up a completely predictable furor. The issue was raised because of Sen. Bernie Sanders’s decision to rally on behalf of a Democratic candidate for mayor of Omaha despite the candidate’s past opposition to abortion. That visible support rankled pro-choice Democrats and prompted Perez to issue his blanket admonition.

That the furor was predictable doesn’t mean that it’s not without nuance. Although the political shorthand on issues of choice tends to be that Democrats support the right to legal abortion and Republicans don’t, there’s broad variance within the parties on the issue of abortion itself and on the scope of what might justify the procedure.

The General Social Survey has asked Americans about their views on abortion for several decades. (The survey, funded primarily by the National Science Foundation, was conducted through in-person interviews with a random national sample of about 1,900 adults in spring 2016.) Instead of a blanket “Are you for or against legal abortion?” question, the survey breaks out responses by party identity and the question by motivation for the procedure. Although “strong Democrats” are more broadly supportive of the ability to have an abortion, there’s support and opposition across the political spectrum and across the rationales for having an abortion.

More than 80 percent of “strong Republicans” agree that a woman whose life is at risk should be able to have a legal abortion. Only about half of strong Democrats think that a woman should be able to have an abortion for any reason. The implication? A lot of Democrats see nuance in how abortion should be available — and a lot of Republicans aren’t universally opposed to the idea.

In the 1970s, opinions on whether women should be able to have a legal abortion for any reason were generally the same among Democrats, independents and Republicans. (Here, we are excluding leaning independents and strong Democrats and Republicans. Essentially, it’s the second, fourth and sixth circles of the first row on the graph above.) Over time, support among Democrats became stronger and support among Republicans slightly lower.

Unsurprisingly, there’s a split along gender lines. Surprisingly, it’s not that large. Overall, the 2016 survey found that 45.5 percent of men and 44.4 percent of women agreed that legal abortion should be available if a women wants it for any reason.

Democratic women have consistently been more likely to support the idea than independent or Republican women, but only since the 1990s.

Democratic men are more likely than independents and Republicans to think that women should be able to seek an abortion for whatever reason — but that hasn’t always been the case. (The variations on this graph are largely a function of smaller sample sizes.)

All of which is a long way of reinforcing the idea that views are nuanced. But Perez, as head of the Democratic Party, isn’t in the business of rewarding nuance. There is a vocal, active and organized part of his party for whom his litmus test was less controversial than it was essential. His litmus test — as it was quickly described — spurred a number of responses demanding or reiterating that the Democratic Party be welcoming to those who oppose legal abortion. (Among those bucking Perez was House Minority Leader Nancy Pelosi, who suggested that there is still space in the party for those who aren’t fervently pro-choice.)

Generally, though, there simply aren’t that many people who vote first and foremost on the issue of abortion. A Gallup poll from May found that one-fifth of Americans say that a candidate he or she supports must share their views on the issue. About 28 percent said it wasn’t a major issue; about half said it was one of many issues.

Perez’s statement was gambling that he could placate the 20 percent who vote on abortion and are members of his party, while assuming that the abortion opponents who are in that group are already voting Republican and that everyone else might look past his comment.

It reinforces, though, the question at the heart of Perez’s tenure: What should the Democratic Party be? Should it follow Sanders’s lead and put economics above everything else? Should it have a strong focus on the diaspora of progressive issues such as choice, offering a big tent for a lot of hard-line positions? Should it simply be the anti-Republican Party?

On Friday, Perez demonstrated how tricky answering those questions will be.