Why, demanded several readers, does this headline refer to race: “These 25 Republicans – all white men – just voted to ban abortion in Alabama.” It was part of the Guardian’s coverage of the southern US state’s new measure. The sole exception to the ban is serious risk to the health of the woman; pregnancies resulting from incest or rape are not excepted. Of the 27 Republican men in Alabama’s 35-seat senate, 25 voted for the law.

Distilled, the readers’ view was that although it was understandable that the headline would emphasise male dominance, it was wrong to highlight race, too. Wrote one: “It detracts and distracts from the real outrage, which is that they’re all male, and they’re all Republican, rather than their skin colour.” Another reader thought that the reference to race implied that the votes were motivated by racism. Another wanted the emphasis to stay on the personal moral beliefs of the legislators, whichever way they voted.

The racial prejudice that has disfigured US history has manifested in electoral systems

Some readers alleged a breach of the anti-discrimination sections of the Guardian editorial standards, which require that journalists refrain from referring to a person’s race or ethnic background unless that information is pertinent to the story. The BBC guidelines express a rationale that is widely shared among journalism codes: “Content may reflect the prejudice and disadvantage which exist in societies worldwide but we should not perpetuate it. In some instances, references to … race … may be relevant to portrayal. However, we should avoid careless or offensive stereotypical assumptions and people should only be described in such terms when editorially justified.”

In this Alabama case, I believe race was highly pertinent. An important aspect of this story is representation, or lack of it. The racial prejudice that has disfigured much in US history, particularly in the south, has manifested in electoral systems, and the effects cannot be left out of account. Of the 50 states, 21 have never sent an African American to Congress.

The Guardian article could perhaps have distinguished and elaborated better the two aspects of inequality, sex and race. The bulk of it was about the imbalance between numbers of men and women legislators. However, space and time always limit journalism, and the story did say: “The Alabama law will disproportionately affect black and poor women, because they are more likely to seek abortions, and less likely to have resources to obtain an abortion out-of-state.”

In essence the article was drawing attention to the unrepresentative makeup of a legislature that had almost entirely outlawed a choice that is a woman’s to make, in a state where the measure would affect some more than others.

The Alabama population of 4.8 million was 51.6% female at the time of the most recent census, 2010. A population that is 69% “White alone” and 27% “Black or African American alone”, to use US census bureau terms, might reasonably expect similar proportions in its state legislature.

The Guardian article reported that the proportion of women in the bicameral, 140-member Alabama legislature is 15.7%, compared with 28.7% across all state legislatures. In Alabama’s senate the proportion of women is 11.4%, with the representation of black women smaller still.

• Paul Chadwick is the Guardian’s readers’ editor