Things to know about federal law enforcement activity in Portland, Chicago, Memphis

President Donald Trump's announcement that he will send troops to Portland, agents clashing with protesters near an immigration enforcement building in suburban Chicago, and the expected arrival of the National Guard in Memphis are the most recent examples of current and possible federal law enforcement crackdowns in U.S. cities. Trump said on social media Saturday that he was directing the Department of Defense to “provide all necessary Troops to protect War ravaged Portland.”