Wisconsin Gov. Scott Walker was mocked for suggesting a wall be built along the border between America and Canada during his short-lived Republican presidential primary campaign. But Homeland Security officials take the idea of terrorists moving into the U.S. from Canada very seriously.
An October 2015 Senate Homeland Security Committee report showed because there are so few Border Patrol agents on the northern border, drug smugglers are able to easily move their products north and south across the border.
Not only is it the longest border in the world, it is one of the busiest. Approximately 300,000 people and $910 million in trade cross the northern border every day, representing the largest bilateral flows of goods and people in the world.
Imagine what could be hidden in that traffic.