About 520k people make the minimum wage. There are close 74 million hourly workers and there are 151m total workers. Therefore, the minimum wage effects 0.3% of workers and 3% of hourly workers. The key stat I saw was 94% of minimum wage earners do not have a college degree while 39% of mimimum wage earners don't have a high school degree.
http://www.bls.gov/cps/minwage2004tbls.htm
Except many hourly workers have their pay built around minimum wage. So all of them would also get raises. Figure probably over half of all hourly workers are effected by minimum wage, even if their hourly rate is nowhere near.