Carl Icahn is known for his political involvement. He endorsed Donald Trump in the 2016 United States presidential election. Beyond politics, Icahn has supported multiple causes through his philanthropy. For example, he has made large donations to his alma mater, Princeton University, and Mount Sinai Hospital in New York. He's also pledged to give away more than half of his fortune. His activism even extends to ethical issues, like pushing for better animal welfare. So, in summary, Icahn supports a mix of political, educational, medical, and ethical causes.