     Before their empire fell, the Romans built walls.    Sadly,
many Americans are all too eager to repeat history.  Witness the
immigration bill slowly making its way through Congress, and the
feverish reactions it has inspired. In exchange for granting
undocumented workers a path to citizenship, Republicans have
demanded a so-called "border surge" that would double the number
of patrol agents in the Southwest and build an extra 700 miles
of fencing. Due to bipartisan prejudice against so-called "low-
skill" migrants, the legislation is also loaded with dangerous
new government controls over the labor market. The Senate bill,
for example, requires employers to post new jobs on a Labor
Department website, certify that no citizen is displaced, and
surrender wage-setting to bureaucrats. Nevertheless, the
conventional wisdom is that the bill will open a floodgate of
foreigners. The Heritage Foundation issued an outlandish warning
about the supposed multi-trillion-dollar fiscal burden of new
immigrants, practical