President-elect Donald Trump on Friday expressed his appreciation to Vladimir Putin over the Russian president’s announcement that he would not expel American diplomats in response to new U.S. hacking sanctions as a gesture to the incoming administration.  The tweet is Trump’s latest nod to Putin, whom he has praised as a strong leader – inspiring considerable backlash from American politicians from both parties who call the Russian president an authoritarian leader who poses a danger to U.S. interests.