To be Union or Not to be, that is the question?

ok, so here is the big question on my mind. please feel free to correct me if i am wrong. i have heard that union nursing is a possibility for some, or should i say one in particular colorado hospital (i don't know any currently that have a nurses union). i have heard only rumors, no facts, so this is just purely speculation. my concern are ...why do we need a nurses union, what could possibly be the advantage? i have seen and heard several sides to the impending question. my opinion, and it is just that, is based on some experience with a union based job, completely unrelated to the nursing world. the union has you pay dues, rightly so to "supposedly" protect your job, though i am not sure exactly what it needs to be protected from. there are many employers out there that are less then desirable, so, in this situation i can understand. however, the union bases their belief system on "seniority". meaning, the more years, the more protection, correct? is the union then essentially protecting the rights of those more seasoned within their conglomerate, or do they represent the less seasoned nurses just the same and with equal enthusiasm? another question, if you work hard, do what you are suppose to and contribute to your work environment, team, hospital and patients with the utmost brilliance, compassion and unflawed character, will the nurse that has been in the company longer, who might not work as hard or as effective get more representation solely based on the years that they have been employed? will they become eligible for advancement opportunities when those that are "more qualified" but have less years in the union will not? i question bringing in any union that will represent a person that contributes less to any career situation just because they have been there longer. a union could possibly represent your rights or safety of those employed? how is that any different from what we can do ourselves with in any work environment? shouldn't your job be safe based on performance rather than "seniority"? shouldn't your hourly wage be based on the effectiveness and contribution that you give to your employer as well as the education that you pursue to better yourself and your patients? what is the union really for? if you work for a truly admirable facility, wouldn't they represent their employees with dignity and listen to concerns regarding safe patient nurse ratios already? without having to go on strike or threaten with a nurses union? if the nursing world and the hospitals or facilities that employ us are that bad to work for, then why even go into nursing? personally, and maybe i see the world through rose colored glasses, i would hope the facility/hospital that i have chosen to work for has the same beliefs, values and mission that i do in life.....to give compassionate, ethical and effective care to those that need it....our patients!