I don't see what's so difficult about it. In conditions of full employment we have something more than bravado with which to resist the shittiness of jobs, because you're not tied to any one in particular - it's easier to move around and firms are more desperate for your labour, so wages tend to rise faster, so you can spend less time working if you like. Full employment conditions make us freer from work, in a way that bluster doesn't.
For these reasons, I don't think full employment is sustainable for capitalism in the long run, which is why an awful lot of macro-policy effort goes into cooling things off should the economy threaten to get there. But it's a worthwhile radical political aim nonetheless, because getting there and staying there would push the system beyond capitalism.
Mike
CB: Yes, the demands for full employment is a reform demand under capitalism that capitalism cannot meet. After masses of workers carry out the struggle for full employment, and capitalism fails to meet the demand, we are closer to mass consciousness that understands that capitalism must go.