Somerset set county district to drug test prospective employees

WJAC-TV, a Central Pennsylvania television station, is reporting that Berlin Brothersvalley School District is going to start drug testing its employees. It includes all positions.
That's a change fromthe district's existing policy, which calls for people who are offered jobs to be given drug tests.
The station reported that the district doesn't have plans to drug text existing employees because that would have to be worked out with the union.
What do you think? Should all prospective employees for school districts have to take drug tests?