"We already have the national guard, why do we need another?"
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Because the charge and charter of the National Guard are confined and do not include fighting crime and keeping the peace when NOT in a contingency environment.  Fighting drug dealers and well-armed criminals is the charge of LEO-- that is the community President Trump is re-enabling to do their jobs with the right equipment.
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"What has the government got in mind for us?"
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No- not in mind "for us," what they have in mind for criminals.  Those fighting Antifa, BLM, and the KKK- those who burn books at Berkeley and violently shut down the free speech of others- those aren't National Guardsmen, they're LEO.
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Since you don't know the first thing about what LEO is up against- the blood, violence, the technically-enabled criminal element that they're up against every day- I'll leave it to them to let us know what they need to take on snipers and armored cartel members.