I'm applying for jobs with event planning companies. At a couple of places where I've applied, the application form says that they require a drug test. I smoke pot sometimes with my friends on the weekend, but it certainly doesn't affect my work. It's just like having a couple of drinks to unwind. Can they make me take a drug test? If I test positive, can they refuse to hire me because of it?
Many people share your feelings that drug testing may be unfair, at least in certain situations. By its nature, a drug test picks up drug use that happened off the job, outside of work hours. Depending on the test and your metabolism rate, the weed you smoked on the weekend may remain detectable for weeks afterward -- long after it has stopped having any effect on your reaction time, sensory perception, and so on. To screen out people who occasionally use recreational drugs, but are never impaired at work, strikes some as unnecessary and intrusive.
So, you may have plenty of company on your side of the philosophical or political argument. As a legal matter, however, you're going to lose this one. Virtually every state allows employers to require applicant drug testing. If you test positive, an employer may refuse to hire you on that basis. A number of states restrict the circumstances in which an employer may require testing of current employees. Often, the employer has to have a reason for testing, such as a reasonable suspicion that a particular employee is using drugs or a workplace accident that suggests possible impairment. Applicants generally don't enjoy these protections, however.
An employer can't force you to take a blood test, in a physical sense. In other words, an employer may not hold you down and take blood against your will, or lock you in the restroom until you produce a urine sample. You have the right to refuse a drug test, and the employer has the right to refuse you a job on that basis.
State laws may impose some procedural rules on how an employer tests. For example, the employer may have to use a certified laboratory or give you an opportunity to explain a positive result. To find out your state's rules on drug testing for applicants and employees, see State Laws on Drug Testing.