BLM has had a moment--a year--since the killing of George Floyd. There was an outpouring of support after Floyd's murder and a continuing torrent of approving coverage of BLM and its issues in most media, particularly elite media, since then.
Yet BLM today is no more popular than it was in fall of 2019 and not only massively down from its peak support after the Floyd killing but considerably down from its popularity in spring of 2020, when people were first made aware of the Breonna Taylor and Ahmaud Arbery killings. Moreover, among Hispanics there has been no improvement in BLM popularity since the beginning of 2020, with about as many unfavorable to BLM as favorable today just as was the case a year and half ago. Moreover, whites, who were about evenly split unfavorable/favorable at the beginning of 2020, are now significantly net unfavorable.
So....what happened? Despite the massive push, the corporate backing and the plethora of Black Lives Matter signs in liberal neighborhoods, the movement's popularity is declining not advancing. From certain quarters the immediate interpretation will be that America is full of stone cold racists who refuse to Face The Truth about our white supremacist society, hence the failure of BLM popularity to hold up. But that leaves out other very salient developments such as the association of some BLM protests with violence and looting, the linkage of BLM with strenuously "anti-racist" ideology and above all the promulgation of the idea and slogan "defund the police" which is still embraced by many activists and supporters. It seems highly plausible that the much of the good will toward BLM generated by opposing flagrant acts of police violence has been squandered by these highly unpopular acts and ideas.
Movements either get broader and smarter over time or they lose momentum. BLM is unlikely to be an exception to this rule.