Raising min wage has little to no effect on the middle class. Someone earning min. wage is not middle class.
True, certainly, of our current minimum wage, which is so low that even the poorest-paying employers tend to start at slightly above it. And yet, we still have something that simply should not exist in America: working poor; people with jobs, in America, and they're poor.
However, by raising it back to a 1970s level, which was at about $12 in 2010 Dollars, and things happen:
1. People barely surviving on $10 - $13 grand a year are raised out of poverty, since their wages will now be $21 - $23 grand a year. Thus a couple, both making minimum wage, now begin nearing the median household income, and can consume at a level that is beneficial to local businesses, spending about $12,000 more into their community, at grocery and clothing stores, electronics outlets, making a car payment on time, and even paying for some night school, etc.
2. People in the delta (>$7.25 - $11.99 / hr) are not only raised up, but now in a position where their employer is pressed to pay them more than MW, to retain the worker, since now he/she can get $12 / hr anywhere in town.
3. People making $14 - $16 in superivisory rolls are now just a couple bucks above MW, and will be less satisfied than they are now, making double the FMW. Upward pressure on those wages, too, will result.
But the real economic benefit is this:
Unemployment drops, and worker confidence returns. Competition for workers, especially more skilled / capable / talented / good looking / and so on, increases. Higher starting salaries are offered. Top talent in companies becomes more confident and expects more frequent raises. Employers, who've been in a buyer's market most of the last 1/3rd century, now have a seller's market, for workers. Wages, instead of trending downward, start going up ... and with it ...
The sale of products goes up. A guy/gal with a truck and mower can actually find folks willing to pay for lawn care. A guy/gal with an idea for a cafe, will have many more customers, and folks spending at higher levels when they come in. Small businesses, and especially start-ups, have far rosier prospects.
It's ******* morning again, in America, to paraphrase Reagan's '84 campaign slogan ... only this time, it's real, and not a credit card recovery. People actually making and spending more, the life-blood of the US consumer economy.