It's called internal national security.  That seems to be a concept that is foreign to right wing thinkers except for those who have joined the thousand or so militias whose mission seems to be to defend only themselves from a government they see catering to loser others.  President Eisenhower got a first hand look at 'internal security' problems when he was a mere major and his assignment was to protect Washington DC from unemployed WWI veterans demanding their service bonuses.  That got ugly and was finally solved by FDR enlisting 25000 of them in the Citizens Conservation Corp....a government program designed to advance the welfare of the poor.