http://whorulesamerica.net/power/congressional_diversity_2018.html (retrieved February 28, 2020)
More than sixty years ago, when C. Wright Mills wrote the classic sociological text, The Power Elite (1956), in which he identified three major institutional spheres of power, the corporate, the political, and the military, almost everyone who held the most influential positions in those arenas was a white man, and the large majority were Protestants who had grown up in privileged economic circumstances. If he had included Congress in his analysis, he would have stated there was one woman (white) in the Senate, and 16 women in the House (all of whom also were white). There were no African Americans or Asian Americans in the Senate, and one Latino senator, Dennis Chavez, who was first elected in 1935 and served in the Senate until 1962. There were two African Americans in the House (Adam Clayton Powell from New York, and Charles Diggs, from Detroit), no Asian Americans, and no Latinxs.
For the past three and a half decades, Bill Domhoff and I have been monitoring diversity in the power elite, and we have included Congress in our analyses (because we think Mills underestimated its importance). We've found that the corporate, political, and military elites have diversified since the 1950s, but at a glacial pace, and in different ways. Women, for example, made it into the corporate and political elites well before they were allowed to join the military elite and African Americans became part of the political elite well before they made it into the highest levels of the corporate elite. As will be seen below, the growth patterns have differed in the Senate and the House, and they have differed for women, African Americans, Latinxs and Asian Americans.
How big a jump did women and people of color make in diversifying the House and the Senate in the 2018 elections? And how much in each group? If we assume, as social scientists do, that every demographic (e.g., women, men, African Americans) would have an equal chance to be in Congress if there were no barriers for them, then the size of the difference between a group's percentage of the population and its percentage of seats in the House or Senate provides an indication of the degree to which each group is excluded and maybe powerless. Would anyone doubt, for example, that white women and all people of color were unrepresented or underrepresented back in the 1950s because they were excluded and lacked power?
First, what about women in Congress? In 1956, the year The Power Elite was published, Margaret Chase Smith, who won a special election to the House in 1940 to replace her husband when he died, then was re-elected to four more terms before she ran for and won a Senate seat in 1948, was the only woman in the Senate. So, a mere 1% were women, when the "expected" percentage, if women had an equal chance of being elected, was about 50%. As for the House, it had 16 women members (3.7%), eight of whom (six Democrats and two Republicans) were widows of Congressmen. Several of them went on to win one or more terms in the House through their own campaigns. The other eight women (five Democrats and three Republicans) started in politics at the local level and worked their way to election to the House in their own right.
Forty-four years later, in 2000, the number of woman in the House had increased, slowly but surely, to 58 (13.3%), and the number in the Senate was up to 9 (9%), As can be seen in Figure 1, which tracks the increases in women, African Americans, Latinxs and Asian Americans in the House of Representatives from 1966 through 2018, the single biggest jump for women came as a result of the November 1992 election, between the 102nd Congress, which had 30 women in the House, and two in the Senate, and the 103rd Congress, which had 48 women in the House and seven in the Senate. The increases as a result of that 1992 election, from 6.7% to 10.8% in the House, and from 2% to 7% in the Senate, which is frequently referred to as "the Year of the Woman," are often attributed to voter reactions (that is, disgust) to the controversial hearings for African American Clarence Thomas' nomination to the Supreme Court. In those hearings, Anita Hill, a black lawyer from Oklahoma, provided gripping testimony that credibly accused Thomas of many indignities and sexual innuendos when she worked for him at the Equal Employment Opportunity Commission (an agency that the ultraconservative Thomas was in the process of undermining).
Since the year 2000, the number of women in the House and the Senate has increased steadily, with each election generally adding a few women (so, for example, in recent elections, the number of women in the House went from 77 to 80 and then to 85. In the 2018 election, though, there was another big jump, one that corresponded to the big increase back in 1992. This time the number of women went from 85 in the 115th Congress (2017-2019) to 102 in the 116th Congress. Women now make up 23.4% of the House.
The increase was almost completely in the Democratic Party. All but one of the 37 newly elected women were Democrats, and the percentage of women among the Democrats in the House increased from 31.6%, to 37.9%. Among the Republicans, almost half of the women incumbents lost (this included a loss by Mia Love, the only Republican African American woman in the House), and there was only one newly elected Republican woman, Carol Miller (R-WV). As a result, there are only 23 Republican women in the House and the percentage of women among the Republicans in the House decreased from 9.8% to 6.5%. Moreover, shortly after the elections, the large contingency of white male Republicans then defeated bids for leadership positions by two incumbent Republican women, and almost defeated a third woman as well.
In the Senate, the 2018 elections increased the total number of women by two. Two incumbent women lost to men, both Democrats (Claire McCaskill, D-MO, and Heidi Heitkamp, D-ND), but two Democratic women, Kyrsten Sinema (D-AZ) and Jacky Rosen (D-NV), won on their initial attempt to win formerly male-held Senate seats after serving in the House, so the two losses were cancelled out. In addition, one appointed female senator, Tina Smith (D-MN), who had replaced Al Franken in December 2017, was re-elected to serve out the final two years of Franken's term. On the other side of the aisle, Cindy Hyde-Smith, a Republican from Mississippi, who had been appointed during the previous term to replace an aging and ill Republican male, won election for the first time in a run-off against African American Mike Espy, and Marsha Blackburn (R-TN) made the jump from the House to the Senate. In December, Republican Martha McSally — who lost the November Arizona Senate election to Sinema — was appointed by the governor of Arizona to replace John Kyl, who had been serving as a temporary replacement for the recently deceased John McCain. The Senate, therefore, will have 25 women: 17 Democrats and 8 Republicans.
What about people of color? African Americans, Latinxs, and Asian Americans have been much more likely to be elected to the House than the Senate — the Senate, of course, requires candidates to appeal to voters throughout the state, not just in the district in which they live. All three groups were at their peak in the Senate in the 115th Congress, with four Latinxs (three men and one woman, two Democrats and two Republicans), three African Americans (two men and one woman, two Democrats and one Republican), and three Asian Americans (all women, all Democrats). These numbers did not change as a result of the November 2018 election.
In the House, however, there were significant changes. Before the election, Africans Americans made up 10.7% of the Representatives, Latinxs made up 9.4%, and Asians made up 3%. As a result of this election, the percentage of African Americans increased to 12.0% (and, notably, eight of the newly elected African Americans won in predominantly non-Hispanic white districts), the percentage of Latinxs increased to 11.3% and the percentage of Asian Americans to 3.2%. For perspective on the meaning of these percentages, it is useful to keep in mind that African Americans make up about 13% of the total population (which means they are close to their percentage of the population), Latinxs make up about 16% of the total population (and significantly below their percentage of the population), and Asian Americans make up slightly less than 6%, which is about twice their representation in the House. All three groups, therefore, are still under-represented in Congress, but they are better represented in the House than the Senate.
The drop in the number of white men in the Senate and the House has been steady and dramatic. When we add the number of men of color to the number of women, and subtract from 435 in the House, and from 100 in the Senate, as can be seen in Figure 2, it is apparent that from 1966 through 2018, the decline in white male representation has been gradual but considerable — from 95% in both the House and the Senate in the 90th Congress, to 59% of the House, and 70% of the Senate. However, it is useful to keep in mind that white men make up only about 35% of the larger population, so even with their losses over time they are very much over-represented.
Moreover, if we factor in party affiliation, we see once again the stark differences in diversity between Democrats and Republicans, as the Democrats have become increasingly diverse, and the Republicans increasingly have become the party of white men. In the new 116th Congress, fully 88.4% of the women and people of color in the House, and 63.3% of the women and people of color in the Senate, are Democrats.
If we expand the definition of diversity to include Jews, Muslims, Native Americans, and LGBT individuals, there is slightly more diversity because 21 of the white men (6.4%) are Jewish. Some of the white men are openly LGBT, two of the newly elected women are Native Americans, and two of the newly elected women are Muslims. Once again, almost all of this diversity is in the Democratic, not the Republican Party: more than 90% of the Jews in Congress are Democrats, as are all of the LGBT, Native American, and Muslim members of Congress.
This past election, therefore, revealed meaningful increases in all dimensions of the diversity that is present in a multicultural nation consisting of descendants of indigenous people, slaves, and immigrants, along with millions of newly arrived immigrants from every region of the world. But the two parties have been going in opposite directions on diversity for more than fifty years. Importantly, the Democrats gained a majority in the House in 2018, which means that the party of diversity will have more leverage as it confronts both an executive branch and a Senate controlled by a Republican Party that has become the party of fiercely conservative white Christian men. The fate of the United States as a diverse and inclusionary nation, as opposed to one with white male dominance in the name of Christianity, racism, and nativism, is increasingly in the hands of the Democratic Party, especially as more and more white women and people of color run for and are elected to Congress as attention turns to the fateful 2020 election.
 Rather than struggling with the complex terminology for those sometimes referred to as Hispanics, Latinos, Latinas, Hispanics, or Chicanos, I will use the relatively new and gender-neutral term "Latinx" throughout the remainder of this article. For a more detailed discussion of this nomenclature challenge, see Richard L. Zweigenhaft and G. William Domhoff (2018), Diversity in the Power Elite: Ironies and Unfulfilled Promises, Rowman & Littlefield, pp. 131-133 and p. 257, note 8.