So I wrote a thing. It is short, simple, and I wanted to write so much more except that would have changed it from a simple definition to an opinion. So here I am.
White people in America (And probably the rest of the western world but I can't speak to that.) have certain privileges that other races do not. Chief among them is not having to worry that racism is going to substantially negatively affect their lives. As a result, the complexities of a racial reality are not something the average white person has to think about. However, given audience reaction when Jane Elliot's asks if any white people would like to treated the same way as black people, white people are not wholly unaware.
I would argue that Rev. Martin Luther King, Jr. actually wrote about the concept of white fragility decades before the term existed. In his letter from Birmingham Jail, 16 April 1963 he writes:
"First, I must confess that over the last few years I have been gravely disappointed with the white moderate. I have almost reached the regrettable conclusion that the Negro's great stumbling block in the stride toward freedom is not the White Citizen's Council-er or the Ku Klux Klanner, but the white moderate who is more devoted to "order" than to justice; who prefers a negative peace which is the absence of tension to a positive peace which is the presence of justice; who constantly says "I agree with you in the goal you seek, but I can't agree with your methods of direct action;" who paternalistically feels he can set the timetable for another man's freedom; who lives by the myth of time and who constantly advises the Negro to wait until a "more convenient season." (Emphasis mine.)
American racism, by hurting all those who are not white, de facto benefits white people. And just like with minorities and Affirmative Action, acknowledging White Privilege can feel as though accomplishments are being devalued. That by itself would make it a hard discussion to have. If only it were that easy.
For the last few years I've been living in Michigan and a chunk of my time has been spent in more rural areas. The plural of anecdote is not data but broadly speaking my experience has been that white people fall into a few categories: Unapologetic racists, apologetic racists, the racially insensitive, woke, and too woke. And just about every member of all of these categories is going to consider the possibility of being called a racist whenever the subject of race and racism is brought up. The thought of that leads to certain behaviors.
Unapologetic racists react by openly defending their racism. Their stance is their views are wholly correct and as such are not a belief but rather facts. They'll probably also claim that white people suffer more racism than other groups.
Apologetic racists, which I also think of as secret racists are people who hold racists views but are aware that such views are not socially acceptable and may even be aware they should not have such views. However, they typically react by reciting the exact same misleading or outright false statistics the above group does, desperately trying to justify their hidden opinions.
The racially insensitive are not necessarily bad people. Typically they think and behave the way they do because they operate on the assumption that racism is a mostly solved issue. By and large they treat people of other races fairly. However, because they don't think of racism as a problem, POC bringing it up as one must obviously be a victim mentality tactic. And the disparity in outcomes along racial lines becomes the seed of racism. After all if racism is over but POC still can't succeed, obviously something is wrong with them. Cue the exact same statistics as the above two groups.
Woke people are okay. They are usually in some stage of learning and realizing how racism plays out in society and it's less obvious effects. Most importantly they are open to learn in order to help.
Too Woke people make actually woke people look bad. Typically they are someone who was/is in one of the first three groups who overcompensates to protect their own ego. Their reaction is generally to virtue signal brighter than a lighthouse instead of actually having a discussion.
All the above reactions that prevent constructive discussion about racism are collectively my general experience of white fragility.
/end meandering rant thing.