Not to be the guy blaring "Fortunate Son" at your Fourth of July picnic, but you know that great jobs report today? There's an ugly little trend hidden in it: America looks like it's back to laying off factory workers.

The economy has gained jobs at a lukewarm-but-steady pace over the last year, a pace that heated up a bit with Friday's news that 207,000 net private-sector jobs were created in June. But manufacturing employment fell by 6,000 jobs in June -- the fourth straight month of job losses in the sector. For the calendar year, factory employment is basically flat, even as overall employment is up:

Other economic data that measure factory output, not just employment, have looked weak lately. So has export growth.

A couple of years ago President Obama was crowing about an American manufacturing renaissance, and the numbers seemed to support him. Factory job growth was an early driver of the recovery from recession. Now, Obama is taking increasing heat from liberal groups that want him to adopt more protectionist trade policies.

Politics aside, the big worry here is that the early days of the recovery look more and more like an outlier, a correction to companies laying off too many workers in the recession  rather than a more sustained reversal of the decades-long drop in factory employment. The plateau of the last year looks awfully familiar, historically, and it's not usually followed by something good: