If Martians were settling here and some of them were preaching war against us and periodically killing us and blowing things up. would we blame radical Martian extremism or would we say that the Martians need to go back to Mars?
Would libertarians insist on a free right to travel between Mars and Earth? Would Republicans demand more off-world workers and tell us how the growing green population is expanding our economy? Would liberals lecture us about the universal brotherhood of intelligent life? Would the media ceaselessly promote pictures of poor, down-trodden little Martian children who just want a better life here on Earth? Would teachers and university professors indoctrinate young people on the shameful injustice of human privilege on Earth? Would our leaders worry about the potential rise of anti-Martian extremism every time a Martian killed someone?
Or would we come to our senses before it was too late and begin sending the aliens home?