Typically used when they get rid of someone in a hurry as opposed to a long, drawn out legal process. Being forcibly removed from a job or home by the police or being ordered out.
Although the net effect is the same, this is substantially more abrupt and nasty than being terminated, evicted or separated from a job.
"I ruined a big job and they gave me the left foot of democracy."
I had a big party again last week; today when I came home from work all my things were outside and the locks were changed. The landlord gave me the left foot of democracy, but my rent was only 3 months overdue.