In his famous address at the 1963 March on Washington, Martin Luther King Jr drew a direct line between the struggle for racial equality and the nation's efforts to realise democracy. “When the architects of our Republic wrote the magnificent words of the Constitution and the Declaration of Independence, they were signing a promissory note to which every American was to fall heir,” King declared. However, King emphasised, the nation had betrayed that promise to Black people: “It is obvious today that America has defaulted on this promissory note in so far as her citizens of colour are concerned.” King warned that this failure meant the nation's promise that “all men are created equal” remained a “dream” that was yet to be realised.

Nearly 60 years later, the Black Lives Matter movement has highlighted continuing racial disparities in policing, education, employment, healthcare and voting rights, again underscoring the yawning gap between the nation’s democratic ideals and its lived reality. Even so, our research shows that Americans remain divided over whether racial inequality is a problem. Although a majority of Americans recognise that White people enjoy racial advantages and are angry about racism in US society, a substantial fraction disagrees.

These disagreements animate the very real, and very perilous, struggle over the survival of US democracy today. People who deny White racial advantages and the prevalence of racial inequities also doubt the legitimacy of the 2020 presidential election, express more positive attitudes towards the January 6, 2021 attack on the US Capitol and absolve former president Donald Trump of blame for the riot.

These patterns suggest that the desire to maintain White advantages — the impulse that King identified as largely responsible for the nation's democratic failures — continues to threaten the wellbeing of US democracy.

How we did our research

Since Trump’s election to office in 2016, scholars have carefully documented the relationship between racial attitudes and support for the former president. They have provided strong evidence that negative attitudes towards people of colour and hostility towards immigrants are closely associated with support for Trump.

Given that Trump's false allegations that the 2020 presidential election was stolen from him relied heavily on racist claims about voter fraud and election manipulation, we suspected that racial attitudes would shape perceptions of the 2020 election and the January 6 attack on the Capitol.

In a survey of a nationally representative sample of 1,000 American adults fielded from December 14 to 20, we asked respondents about their views on racism in American society — specifically, whether they agreed that White people enjoy advantages based on skin colour or that racial problems were isolated situations, and whether they were angry that racism exists (items from the FIRE scale, which stands for fear, institutionalised racism, and empathy). We also asked about their perceptions of the legitimacy of the 2020 presidential election and their views on the events of January 6.

What we found

The patterns we found were revealing. For example, although 58 per cent of Americans agree that White people have advantages, 15 per cent said they were neutral, and 26 per cent disagreed. (Among White people, 55 per cent acknowledge White advantages and 30 per cent disagree.) Twenty-five per cent of Americans believe racial problems are just rare, isolated situations, while another 15 per cent express a neutral view of this matter, compared with 60 per cent who say that racial problems are more common. We highlight the neutrals as well as those who explicitly play down racial inequities because King famously warned against “lukewarm” or moderate responses to racial injustice.

These divisions over racial equality were closely related to perceptions of the 2020 presidential election and the Capitol attack. For example, among those who agreed that White people in the United States have advantages based on the colour of their skin, 87 per cent believed that Joe Biden’s victory was legitimate; among neutrals, 44 per cent believed it was legitimate; and among those who disagreed, only 21 per cent believed it was legitimate. Seventy per cent of people who agreed that White people enjoy advantages considered the events of January 6 to be an insurrection; 26 per cent of neutrals described it that way; and only 10 per cent who disagreed did so, while 80 per cent of this last group called it a protest. And while 70 per cent of those who agreed that White people enjoy advantages blamed Trump for the events of January 6, only 34 per cent of neutrals did, and a mere 9 per cent of those who disagreed did.

Similarly, 81 per cent of people who recognised that racial problems were more than just rare, isolated situations believed that Biden's election was legitimate, compared with 39 per cent of neutrals and 32 per cent of those who thought that racial problems were rare. And 66 per cent of those who agreed that racial problems were more than rare situations blamed Trump for the events of January 6, compared with just 35 per cent of neutrals and 13 per cent of those who thought racial problems were rare.

Racial attitudes matter among both Democrats and Republicans. For example, among Republicans who agree that White people enjoy advantages, 37 per cent believe Biden’s election was legitimate, but among those who don’t, only 14 per cent do. Meanwhile, among Democrats who agree that White people enjoy advantages, 96 per cent believe Biden was legitimately elected, but among Democrats who disagree, only 76 per cent do. For independents, 89 per cent of those who believe White people have advantages think Biden's election was legitimate, but only 20 per cent of independents who don't think white people have advantages do.

Divisions over racial equality and the struggle for democracy

These patterns reveal that the wounds that King identified exist still. A majority of Americans acknowledge the reality of racial inequality in US society today. However, as King would have predicted, those who deny the existence of racial inequality are also those who are most willing to reject the legitimacy of a democratic election and condone serious violations of democratic norms. For this reason, and as King argued, advancing racial equality and renewing US democracy go hand in hand.

• Jesse H. Rhodes is professor of political science at the University of Massachusetts Amherst, associate director of the UMass Poll, and coauthor (with Brian F. Schaffner and Raymond J. La Raja) of Hometown Inequality: Race, Class, and Representation in America's Local Politics (Cambridge University Press, 2020). Raymond J. La Raja (@raylaraja) is professor of political science at the University of Massachusetts Amherst, associate director of the UMass Poll, and coauthor (with Brian F. Schaffner) of Campaign Finance and Political Polarisation: When Purists Prevail (University of Michigan Press, 2015). Tatishe M. Nteta (@TatisheNteta) is associate professor of political science at the University of Massachusetts Amherst and director of the UMass Poll. Alexander Theodoridis (@AGTheodoridis) is an associate professor of political science at the University of Massachusetts Amherst and associate director of the UMass Poll