The guaranteed job will consist of a variety of mental and physical tasks that can be easily monitored either online or within existing institutions. The mental tasks might be activities such as keyboarding practice, doing arithmetic exercises on an internet training program, doing exercises in word processing, doing spread sheets, reading reports and summarizing them, or completing online courses. The physical tasks might include doing specific exercises, digging holes and filling them, moving weights, and other similar type activities. The goal of these activities is not to produce usable output for society, but to provide work activities by which people can translate their time into income. To the degree possible, these working experiences will provide training in skills and an introduction to customs and behavior useful in the real-world market jobs
The US labor force is currently around 160 million people, with a 5% UE rate some 8 million people are going to be eligible for this work, assuming only 1 in 10 decides to take the government up on the offer and assuming that zero people out of the labor force get pulled back in the Federal Government will be providing jobs for 800,000 people at any one time. Of course the "safety net" is most important during times of trouble, during the last recession the UE rate peaked near 10%, to provide jobs during a period like that would result in the government running an industry of 1.6 million people. Wal-Mart is the largest employer in the US and has fewer than 1.5 million employees here.
Of course the honor system doesn't work so you need to have people oversee these activities, and managers to organize and watch the overseers (and again and again), along with payroll, legal departments (for when someone claims repetitive stress disorders from doing to prescribed activities), HR departments so people can complain that their website is down/they didn't get paid/their disabilities aren't catered to, coders on the front and back end of websites and all manner of other positions.
It is basically inevitable that this program, if it was at all successful, would become the single largest employer of people in the US, its "employees" will almost certainly agitate to form a union at some point (with some bizarre potential complications) and all of this is going to have to be designed in a way to double in size within a few months during a recession.
The most obvious blind spot in politics these days is that the sheer size of proposed solutions are generally brushed aside. I mean if Wal-Mart can build a labor force of 1.5 million over decades, then surely the government can build something even bigger with a few pen strokes, a few good intentions and a 5 page proposal outlining the finer points.