This is one thing that I have seen for years and it really upsets me about employers. People get called for a "temp" position when it is just really about keeping the number of full-time employees down. You can be a "temp" for years. When a full-time employee quits or retires after years at a position, they are replaced by a "temp" that will do the job for a fraction of the pay and has diminished benefits.
This is one thing I would hope the states or fed would take up. Define a temp job to a set amount of time. Then hire them.