The Bureau of Labor Statistics compiles a wide range of employment statistics on private sector establishments. Collectively referred to as Business Employment Dynamics, private sector job gains and losses can be found under the BLS Subject Areas header, and statistics can be accessed through the data servlets available under the Databases and Tools header. Data on total private sector jobs are available under CEU series Id 0500000001, formatted as monthly totals that net out monthly gains vs. losses.
The following graph displays private sector job creation for the post-war period, spanning the presidential tenures Ike through Obama as of June 2012. The data points are operationalized as monthly average change in private sector jobs by presidential tenure, from the month preceding their first full month in office .. to last month in office. The non-seasonally adjusted time-series data is sourced from BLS data servlet CEU series ID 0500000001 available (click) here:
Change in Private sector jobs over the post-war era, Ike thru Obama:
As the historical record shows, private sector job creation over the post-war tenures Ike thru Obama has been far stronger under Democrat administrations. In the aggregate, the post-war economy generated an average 146,000 jobs per month in office over Dem presidential tenures as opposed to 58,000 private sector jobs per month under GOP tenures, yielding a Dem/GOP ratio of 2.5.