The Democratic Party relies on Black women to be the most consistent and engaged progressive constituency, but rarely supports their political leadership. A group of 27 Black female political advocates and leaders released an open letter demanding that Democratic National Committee (DNC) chairman Tom Perez stop taking them for granted.

"We have voted and organized our communities with little support or investment from the Democratic party for voter mobilization efforts," reads the letter, which was published bt NBC BLK yesterday (May 24). "We have shown how Black women lead, yet the party’s leadership, from Washington to the state parties, have few or no Black women in leadership. More and more, Black women are running for office and winning elections—with scant support from Democratic Party infrastructure. Well, like civil rights activist Fannie Lou Hamer, who testified at the 1964 Democratic convention demanding Blacks have a seat and voice within the Party, we are ‘sick and tired of being sick and tired.’"

The letter’s signatories include elected officials like U.S. congress members Marcia Fudge and Joyce Beatty (both D-OH) alongside advocates like Women’s March co-chair Tamika Mallory and Higher Heights for America‘s Glynda Carr and Kimberly Peeler-Allen. The group collectively recognizes electoral victories by senator Kamala Harris (D-CA) and state-level politicians that, despite their strategic importance, did not compel Black women’s inclusion in DNC leadership:

Black women also made important progressive wins in Minnesota, where IIhan Omar became the first Somali-American Muslim elected to the state legislature; Kentucky, where Attica Scott became the first woman elected to the state legislature in 20 years; Cook County, Illinois, where Kim Foxx was elected state’s attorney; Orange County, Florida, [where Aramis Ayala became] the first Black state’s attorney in Florida’s history; the state of Texas, [which] elected its first woman Sheriff, Zena Stephens; and Jefferson County, Alabama, [which] elected nine Black women to the judicial branch.

This February, in the DNC elections, we saw an increase in overall diversity within the officer ranks, but no increase in leadership representation of Black women. Since taking office, you have met with and listened to key constituencies. But you have yet to host a Black women leaders convening.

"Organizing without the engagement of Black women will prove to be a losing strategy, and there is much too much at stake for the Democratic Party to ignore Black women," the signers continue. "In the absence of our inclusion in discussions about the Party’s forward movement, we question whether the Party values our loyalty and takes our commitment seriously."

The letter ends with a call for Perez to meet with Black women leaders, which he has yet to publicly confirm or reject. Read the full letter on NBCnews.com.