It's a pretty simple calculus, really, but no one's pointing it out. Cowardly Democrats and craven Republicans want unemployment benefits to expire, so the argument goes, so that people will get off their duffs and go get jobs. This theory assumes that there is a glut of jobs out there going unfilled.
The situation they are describing is what happens in times of full employment, not an economic downturn. The problem is not that a half million jobs are going unfilled; the problem is that there are a half million fewer jobs than applicants. This is not difficult to understand.