Ever wonder why unions care so much about the minimum wage when almost all union members get paid above that level? The answer is simply, but sleazy. As Walter Williams explains, they want to protect their high-pay status by increasing the cost of lower-skilled workers. For all intents and purposes, they are pricing poor people out of the job market:
Labor unions are the major supporters of increases in the minimum wage. Even though the overwhelming majority of their members earn multiples of the minimum wage, they spend millions upon millions lobbying for minimum wage increases. They do it because higher minimum wages protect their members from competition with low-skill, low-wage workers. Most other minimum wage supporters are decent people with a concern for low-wage workers, but their actions suffer from a misguided vision of how the world operates.
http://townhall.com/columnists/WalterEWilliams/2010/05/26/minimum_wage_cruelty_update