In the nearly 232-year history of the US Senate there have only been 11 Black senators

(CNN) - Congress set a new diversity record this year with its highest-ever number of women and racial minorities, including 60 Black lawmakers. But that's mostly in the House.

In the nearly 232-year history of the US Senate there have only been 11 Black senators
People of color have historically had a tougher time getting elected to the Senate. Newly elected Raphael Warnock is only the 11th Black US senator since the Senate convened for the first time in 1789. Only two of those have been women. And with the departure of Kamala Harris, the number of Black female US senators is now at zero.
Voters in urban congressional districts tend to be more diverse and politically progressive, driving the higher number of minorities in the House. But that has had little effect on the number of Black senators.
"Black US Senate candidates, and especially Black politically progressive Democratic candidates, have found it difficult to get traction and win statewide elections due to the default political conservatism in White majority regions of the US," says Karlos Hill, chair of African-American studies at the University of Oklahoma.
From slavery and Jim Crow laws to suppression of minority voters, Black political candidates have long faced stumbling blocks. Hiram Revels, the first Black US senator, took office in the late 1800s as part of a wave of African American lawmakers during the Reconstruction era, but he was elected by the Mississippi legislature, not the state's voters.
Decades of voter suppression has limited Black voting power in the South, says Tobin Miller Shearer, director of African-American studies at the university of Montana.
Shearer also cites the "incomplete legacy of the 15th Amendment," which granted everyone the right to vote but was undermined by states in the deep South which disfranchised Black voters through literacy tests, property ownership requirements and other racist measures.
It wasn't until 1965 that these discriminatory voting practices were outlawed by the federal Voting Rights Act.
Half a century later Black voters in the South are wielding new power, thanks in part to a push by former Georgia gubernatorial candidate Stacey Abrams and other organizers to register new voters and combat voter suppression.
"Black candidates can compete and win competitive statewide races if they are able to effectively mobilize the Black electorate," Hill says. "If the momentum created by Abrams and Warnock's recipe for mobilizing the Black electorate can be sustained, we could begin to see more Black representation in the US Senate. Only time will tell."