To understand ObamaCare’s impact on part-time employment, consider the six-month period between the employer mandate’s initial “look back” date of Jan. 1 and July 2, 2013, when the administration wisely announced it was delaying the employer mandate for a year. This is the period during which employers most significantly increased part-time employment in reaction to ObamaCare.

The health-care law’s actual consequences unequivocally appear in the jobs data for this period. Between Jan. 1 and June 30, according to the Bureau of Labor Statistics, the economy added 833,000 part-time jobs and lost 97,000 full-time jobs, for net creation of 736,000 jobs. In reality, the economy overall added no full-time jobs. Rather, it lost them.

It’s not like this six-month boom in part-time jobs went unnoticed. In July, Federal Reserve Chairman Ben Bernanke questioned whether the official unemployment rate fairly represented the state of the labor market because it didn’t reflect factors such as “underemployment, part-time work.” Also in July, three powerful unions wrote to the Obama administration complaining that ObamaCare would “destroy the foundation of the 40-hour work week that is the backbone of the American middle class.”