How Public Opinion Has Moved on Black Lives Matter

American public opinion can sometimes seem stubborn. Voters haven’t really changed their views on abortion in 50 years. Donald J. Trump’s approval rating among registered voters has fallen within a five-point range for just about every day of his presidency.

But the Black Lives Matter movement has been an exception from the start.

Public opinion on race and criminal justice issues has been steadily moving left since the first protests ignited over the fatal shootings of Trayvon Martin and Michael Brown. And since the death of George Floyd in police custody on May 25, public opinion on race, criminal justice and the Black Lives Matter movement has leaped leftward.

Over the last two weeks, support for Black Lives Matter increased by nearly as much as it had over the previous two years, according to data from Civiqs, an online survey research firm. By a 28-point margin, Civiqs finds that a majority of American voters support the movement, up from a 17-point margin before the most recent wave of protests began.

The survey is not the only one to suggest that recent protests enjoy broad public support. Weekly polling for the Democracy Fund’s U.C.L.A./Nationscape survey shows a significant increase in unfavorable views of the police, and an increase in the belief that African-Americans face a lot of discrimination.

Perhaps most significant, the Civiqs data is not alone in suggesting that an outright majority of Americans agree with the central arguments of Black Lives Matter.

A Monmouth University poll found that 76 percent of Americans consider racism and discrimination a “big problem,” up 26 points from 2015. The poll found that 57 percent of voters thought the anger behind the demonstrations was fully justified, while a further 21 percent called it somewhat justified. Polls show that a majority of Americans believe that the police are more likely to use deadly force against African-Americans, and that there’s a lot of discrimination against black Americans in society. Back in 2013, when Black Lives Matter began, a majority of voters disagreed with all of these statements.

Will the recent shift in opinion last? News events can sometimes cause a shift in public opinion that quickly dissipates. After mass shootings, for instance, big spikes in support for gun control typically ebb as soon as memories of the bloodshed fade.

But there are reasons to think that the Black Lives Matter movement might be different. For one, the shift continues a long-term trend in public opinion that preceded the death of Mr. Floyd. By the time of the 2016 election, many white liberal Democrats held some views on race that were to the left of African-Americans over all, in what some branded the “Great Awokening.”

Perhaps surprisingly, the election of Mr. Trump may have helped move public opinion even more. There’s a longstanding tendency for voters to drift toward the views of the party out of power on various issues, sometimes called thermostatic public opinion.

And whether on gay marriage or civil rights, American public opinion tends to drift toward the side advocating equal treatment. Public opinion doesn’t have nearly as clear a record of drifting toward the left on issues that don’t hinge on equal treatment under the law, like gun control and abortion.

With a majority of Americans backing the protests, it’s also possible that steps by political actors could move opinion further. The support of Republican elected officials, like Senator Mitt Romney, could give permission for some potentially sympathetic Republican voters to re-evaluate their views on the issue. In general, public consensus becomes likelier when the two parties reach a consensus.

Of course, it’s also possible that events could move public opinion the other way. The tactics of some protesters could be a factor. Kneeling during the national anthem may be less effective at appealing to persuadable Americans than the recent peaceful protests, for instance. A sense that protests were getting out of control, with looting and violence, could also harm the public image of the movement. And it is possible that the movement will face fresh obstacles as it transitions from a critique of the status quo to proposing new policies. Some of the policies under discussion, like defunding the police, may hold more limited support than police reforms.

There’s no way to know what will happen next. After all, no one just a few years ago would have predicted that a majority of Americans would say they have a favorable view of Black Lives Matter.