Workers should be allowed to form unions and engage in collective bargaining for wages and benefits. Unions provide workers with the means and ability to improve wages, working conditions and workplace 'due process' for complaints.
Take the fast food industry, they have a business plan that depends on low-paid (most commonly minimum wage) workers, without benefits simply because the workers don't have the ability to engage in collective bargaining. McDonalds has reported record profits in the past 5 years while at the same time their average wages have remained the same. Without unions companies profit at the expense of their employees' wages.
It is a workers right to be able to unionize. The key to doing things like that is knowing your rights, and having people there to support you and the other workers are on the same page as you. As long as no one tries to go beyond what they are allowed to do by law, they should be able to.
I am normally conservative and don't support unions. They can be harmful for business, and in fact wield too much power. Union bosses get too powerful. Although I don't support unions, I do know that there is some good to them. As far as employee welfare and safe work conditions, nothing beats a union. But as for bullying companies and causing work disruption, unions can be bad. However, it is a fundamental right of ours to be able to form a union.
Workers should be allowed to unionize if they wish too. Some businesses do not listen to those who are much farther down on the ladder pole and will only listen once forced to. If the only way those workers are going to get the benefits, and pay, they deserve then yes, they should unionize.
In this day and age where more and more rights of the workers are being taken away from them it is not the time to take away from unions. Without the unions most workers would be at the mercy and restrictions of their employers whose first duty is to the bottom line or shareholders rather than to the people who help keep their company afloat. Unions were started because employers were allowed to use and mistreat their employees however they deemed fitting. They were started for a reason and should not be allowed to be dismantled.