Workers who didn't get another job for a year typically suffered an 18 percent pay loss. The experience now may be worse because the job market is weaker.
There's a second reason why a strengthened labor market is pivotal for Obama: the young.
Many recent high-school and college graduates can't find full-time jobs or jobs that fit their skills. Careers, marriages and births are being delayed.
Until the labor market strengthens, these workers are particularly vulnerable, because - as the old cliche goes - they're the last hired and the first fired.
Obama's problem is that, because job creation mainly occurs in the private sector, the president's influence is mostly indirect.
One pathway is to try to spur hiring by juicing up the economy through deficit spending.
But recent deficits ($5.1 trillion from 2009 to 2012) have created a political backlash, and some economists are skeptical about deficits' effectiveness.
This option seems off-limits.
A more general approach is to bolster confidence among businesses. The trouble is that Obama's relations with the business community have been rocky.
An obvious flashpoint: the president's proposal to raise the top personal income tax rate from 35 percent to 39.6 percent for couples earning more than $250,000.
Small-business organizations have objected, arguing that many small businesses pay taxes at the personal rates and that higher rates would discourage job creation.
The first test of the post-election political climate will come when the president and congressional leaders try to avert the "fiscal cliff" - the roughly $500 billion in tax increases and spending cuts scheduled for 2013.
The Congressional Budget Office and others have said that if all the changes took effect, the economy would probably plunge back into recession.
For jobs, that would be a disaster.