Possible Clues:

• What the aliens do in 'The War of the Worlds'
• Enter country by force
• Enter en masse
• Navy regularly gets idea to encroach upon others.
• Occupy
• Enter (a country) illegally
• Railed audibly as trespassers do
• Storm in Virginia: 'Lower classes should be in their proper place'
• Trespass upon
• Attack a Democrat in comic vein