While President Obama was tweaking the Affordable Care Act Thursday to extend expiring insurance policies for another year, U.S. Rep. John Kline was holding a hearing in his Education and Workforce Committee to explore another potential pitfall of the law.

In a new challenge to the health care overhaul, the Minnesota Republican has been highlighting the financial burden that it could impose on school districts and colleges that have to comply with the federal mandate to provide coverage for their employees.

Though the mandate has been pushed back a year, educators and school district officials from around the nation warned of the unintended budget consequences of covering part-time and semi-part workers such as teaching aides, adjunct instructors, cooks, bus drivers and others who work more than 30 hours a week.

A recent analysis of Minnesota Education Department data by the conservative-leaning Watchdog Minnesota found that 22,800 non-licensed school employees work between 30 and 39 hours a week, making them eligible for required benefits under the new health law.

State education officials did not immediately respond to a request for comment.

Critics of the law warn that the 30-hour threshold will force schools, just like other employers, to limit hours, cut jobs, or incur greater costs.

While some educators have asked that the coverage threshold be raised to 40 hours, Democrats on the committee argued that the change would hurt part-time workers who will otherwise be insured.

Kline argues that the law's employer mandate could hurt the educational system at all levels. "Americans continue to express their concerns about Obamacare and the troubling impact it is having on their lives," Kline said in the lead-up to the hearing. "Our nation's schools are not immune to the consequences of this law."