Biden Inc.

Over his decades in office, ‘Middle-Class Joe’s’ family fortunes have closely tracked his political career.

The day the Bidens took over Paradigm Global Advisors was a memorable one.

In the late summer of 2006 Joe Biden’s son Hunter and Joe’s younger brother, James, purchased the firm. On their first day on the job, they showed up with Joe’s other son, Beau, and two large men and ordered the hedge fund’s chief of compliance to fire its president, according to a Paradigm executive who was present.

After the firing, the two...