1) They raise prices so those not in unions get poorer because of the high priced union junk they must buy. No net benefit is possible to workers. 2) Unions drove perhaps 30 million jobs off shore with their high wages. No net benefit to workers is possible. 3) Unions encourage people to get ahead through violence rather than by being worth more in the market place. 4) Politicians encourage unions as a source of money, but politicians unions and non union workers don't have the IQ to know that no net benefit to workers or consumers is possible.