I agree Whites are the ones who are (probably) the subgroup where participation in identity politics has experienced he greatest growth by far. But it's not just a matter on how many
take part in it but in how far
things are taken to.
For instance, concepts like "colorblindness" are now being regarded as undesirable by both racists and anti-racists alike regardless of the race/ethnicity of those involved, even though it has the virtue of "de-binarizing" the debates around race. That was definitely not the case a few decades ago. The fact that a substantial number of Whites is adopting a form of identity politics centered on victimhood is also relevant in its own right - having two opposing sides regarding each as being victims is the recipe for deadlock.
Furthermore, we are also experiencing some multipliers that also help to exacerbate these issues. One of them is the rise of social media, which makes it possible to communicate with a lot of people in real time almost anywhere (for the first time in human history for that matter), helps to spread all the identity-centered ideologies along with making it easy to engage in moral grandstanding
and the current format which punishes long posts makes it hard to add some nuance to any claims (because nuanced arguments are usually long), thereby extending and exacerbating identity politics (and extremism in general). Another is the current wave of irrationalism that is currently invading Western societies, which is a separate problem in its own right and allows people to come up with all sorts of ridiculous beliefs (e.g. conspiracy theorists of all stripes, flat-earthers, anti-vaxxers, etc). At last, we're also experiencing a labor-replacing automation that naturally has some large short and medium term costs for any society, even if it's necessary for its long-term economic development.
If I had to make a parallel to the past, the best one would not
be the Civil Rights Movement. The best one would be more like the European romantic nationalism of the 19th century, which also took the form of an exacerbated identity politics not seen since the Wars of Religion of the 16th and 17th centuries. The 19th century also saw, as a result of the first wave of the Industrial Revolution, both labor-replacing automation of many jobs (some of which would disappear throughout the 19th and early 20th centuries) and a greater access to cheaper communications owing to the much lower costs of print texts (a result of industrialization of printing); and also saw its own wave of irrationalism in the form of Romanticism and a pushback against the rationality advocated by the Enlightenment. And yes, this was an example of exacerbated White identity politics as well.