The reason the underpaid, or 39 hours worker with no benefits, needs the card check tool is to bring the worker back to the possibility of getting a union where they work. We used to have a good National Labor Relations Board (NLRB), which enforced the labor laws, but over time, just like the tax laws, loop holes were found by the union busters, some who were ex-labor lawyers who went into a very large new industry of busting unions and disrupting elections.
They would advise owners to intimidate their workers by telling them they would close their shops or move them. They would fire some, give raises or promotions to others. All this was against NLRB laws, but they still did it. The loop hole was the time it took to set up and execute the election. With card check, the workers only need 51 percent of the workers signing a card stating they would like to form or join a union. The employer and employees would have to sit down and negotiate the conditions for the contract for the workers.
That is all card check entails.