You are a dumbass

Wat

You're clearly not too smart, so here's the explanation;

Clown cars, while small have large numbers of clowns falling out of them for comedic effect.

The "Boat" in this joke implies there would be thousands of clowns storming a beach for the same reason as the car gag.

This isn't aimed at migrants. You're overly sensitive. Log off and touch grass.