then, once those people weren't in unions, they pointed at the good deals that union employees got through collective bargaining. This fostered jealousy and created a sentiment akin to "we have a shitty deal, they should have one too"

So now you've got one group of working class people with better salary and benefits than another group of working class people, and a group of politicians saying that the reason that the non-union employees aren't doing better in life is because of the unions.