By Clare Duffy, CNN Business

(CNN) -- A group of Democratic women leaders is calling out sexist coverage of female Democratic vice presidential contenders — and they're asking that newsrooms do better.

In an open letter to top newspaper and network executives, the group said newsrooms should not merely pay attention to problematic stereotypes of women being considered for the position, but "to actively work to be anti-racist and anti-sexist in your coverage."

The letter was signed by roughly a dozen women, including leaders at the National Women's Law Center, Planned Parenthood, TimesUp, Supermajority and more.

Presumptive Democratic presidential nominee Joe Biden has said he will soon select his running mate, and people close to the process told CNN he is believed to have narrowed his personal shortlist to a handful of women. California Representative and Congressional Black Caucus Chair Karen Bass, California Senator Kamala Harris and Susan Rice, Barack Obama's former national security adviser, are believed to be among the most serious contenders.

In the run-up to the selection, discussion and coverage of the women candidates have included sexist tropes, such as criticism of candidates' ambition and questions of electability.

"We've seen so many disappointing things," Hilary Rosen, a Democratic strategist involved in the group, told CNN's Brian Stelter on "Reliable Sources" Sunday. "A mocking of Kamala Harris' ambition, as if every politician running for president is not ambitious," she said. "Whether or not candidates are likable. There were just so many examples that kind of nauseated us."

Errin Haines, editor-at-large for The 19th* who has covered the vice presidential contest, concurred. (Haines was not involved in the writing of the letter.)

"We're all waiting to find out who Joe Biden is going to pick as his vice presidential running mate, but what is known are a couple of things," she told Stelter. "One, that she will be a woman. And the other is that she can expect to be attacked, vilified and criticized for daring to have ambition, capability and a voice in American politics."

The letter calls on newsrooms to improve their coverage of women in politics much as they have by reassessing their coverage of race, as well as their own internal issues with systemic racism, in the wake of the protests over George Floyd's death earlier this summer.

In the weeks and months following Floyd's death, newsrooms have reconsidered how they cover such issues — including what wording they should use and who is, and isn't, involved in reporting and leadership.

"That action included being more careful about the choice of narratives for stories, including more Black people and people of color on the front lines of reporting and behind the scenes producing and editing," the letter reads. "In short, the times and the experience made you, the most powerful people in media, stop and think about your role in perpetuating inequality and the opportunity you had to promote equality and simple justice with your reporting of the news."

Said Rosen: "What we're saying is: you ought to have this same kind of thinking around covering a woman."

In addition to sexist portrayals, the letter points out that Black women and other women of color vying for the VP position stand to face more unwarranted scrutiny and stereotyping.

"For the women of color in this conversation, what we have seen is a disrespect that is a dual assault on their race and gender," Haines said.

Taking on these issues is a natural continuation of the conversations newsrooms have had in recent months, according to the letter.

"Anything less than full engagement in this thoughtful oversight would be a huge step backwards for the progress you have pledged to make to expand diversity of thought and opportunity in your newsrooms and in your coverage," the letter reads.