The petit bourgeoisie takes up a fairly special position in the marxist notion of class division. While the two main categories remain the (haute) bourgeoisie and the proletariat, those who own the means of production and those who don't, this subdivision will form from the proletariat during times of economic growth and prosperity. They're a varied bunch: from small shopkeepers to bureaucrats and politicians to well-off farmers.

Their unifying characteristic is that their economic circumstances have led them to turn away from identifying as a proletarian, with them instead turning towards the haute bourgeois. After all, economically speaking, they're no longer bound to the factories or the fields of someone else. They have reached a level of economic stability that most of the proletariat can only dream of. So they stop seeing themselves as part of the working class, and instead turn to the haute bourgeoisie.

This turn involves taking over and emulating the worldview and morals of the bourgeois. With it comes a loss and rejection of the idea that there's a systemic reason why the rich are rich and the poor are poor. They're not just what comes down to a boil on the head of the proletariat. No, they're the step between both classes, part of the natural progression from one to the other. The way to the top is open and all they need is to put in the work.

The reality is of course different. Capitalism goes into crisis every few decades, and sooner or later one of those crises will be large enough to also start affecting the petit bourgeois. They don't have the systemic safeguards (partially built in by a state which they will find out the hard way carries water only for the haute bourgeois) the actual bourgeoisie does, so they find themselves under pressure. Suddenly they do have to worry about paying their bills. They do run the risk of losing their jobs. But, having foregone any sort of class awareness, they are at a loss as to why this is happening. They just know that it is happening.

No longer equipped with a systemic answer, they turn towards the individualism they took on from the haute bourgeoisie. Someone is to blame for their economic woes. Someone is preventing them from taking that final step towards joining the elite. But who? The poor and the rest of the proletariat - who unlike them are lazy and shiftless, who just won't put in the necessary work to rise from their station. The marxists, the socialists, the union militants who fill the proles' heads with lies about why they have not, and who hurt the nation's welfare with their strikes and demands for better working conditions. But also the foreign powers, who conspire against us and prevent us from taking our rightful place in the sun.

But the petit bourgeois also look up and can't help but see the horrors of the capitalist system - be in the form of the landlord who threatens them with eviction, the bank who won't give them another loan, the wealthy getting away with things they can't get away with. The answers the liberal factions of the bourgeoisie provide them - about the free market, about the ideals of the enlightenment, about the fairness of capitalism - suddenly start to ring hollow. After all, they don't explain why the petit bourgeois are suddenly under pressure too.

But they have fully bought into the bourgeois ideology. So there must be an individualistic factor combining these examples. And somewhere, someone suggests a factor: these people, the people who wield such great influence over your life, and who clearly got to where they are by means of deceit and theft rather than hard work (surely!) - what if they're Jewish?

And that's where fascism comes in. Other forms of fascism than that present in Germany might choose a different scapegoat that the Jewish people, but they always find someone. In Germany, at least, the petit bourgeoisie was a very solid base in Hitler's rise to power.

And herein lies the marxist critique of the petit bourgeois. The petit bourgeois is a subdivision of the proletariat which rejects its class position in favour of aspirations towards belonging to the haute bourgeoisie. This position will come under pressure as they inevitably come face to face with the realities of the capitalist system, from which they are very much not shielded. This pressure leads to friction between their material reality and the beliefs they hold. They refuse to accept the marxist answer as to what's happening, while at the same time their material reality is completely at odds with the traditional liberal capitalist view which they bought into before. This makes them uniquely vulnerable and attracted to fascist ideologies - which provide a narrative which seeks to ease this friction, albeit with pure bullshit.

So not only does the petit bourgeoisie weaken the position of the working class by essentially betraying them, this betrayal eventually leads them to become openly hostile to the working class in the long run.