The problem isn't that the workers are illegal, the problem is that employers are able to pay below minimum wage with no benefits (social security, worker's comp, unemployment insurance, etc.) If we legalize those already here, the employers will still seek out more illegals to continue paying low wages with no benefits. After the first amnesty under Ronald Reagan, there was a huge influx of new illegals into the country. The solution to the illegal immigration problem is to punish employers who hire them.
and the newly legalized will be unemployed, have a 3-year permit to stay in the country, and will probably have access to welfare, unemployment, and other benefits. The worker who participates in the guest worker program actually makes himself less hireable.