What is the difference between buying on margin and a margin call

The proposed downtown mall development will cause severe economic harm to our city. i, like everyone else here, am concerned about the troubled economy, and we all know the importance of job creation — especially here - but these concerns shouldn't push us to blindly support supposed "job creators" without first looking at the data. the truth is that when jobs are created in one place, they're usually destroyed somewhere else. studies have shown that for every job created by a mall, at least one job in a local business is lost. as the former owner of two long-standing small businesses in our community, i know all too well the power of these big commercial chains. my fellow citizens, we have watched this evil evolve for decades, and it's time to take a stand. these new chain stores may be able to offer lower prices on some goods, but they also take money out of our community to pay distant executives and shareholders. if we oppose what is the author's point of view?