Former President Obama on Friday lamented the state of politics today, calling out his successor, Donald Trump, by name as he started his push to ramp up Democratic energy for midterms. Mr. Obama made his return to the political arena by giving a speech at the University of Illinois at Urbana-Champaign after receiving the Paul H. Douglas Award for Ethics in Government. He praised America’s accomplishments but said there is a darker side to progress when politicians peddle resentment and mistrust to preserve the status quo. “It did not start with Donald Trump. He is a symptom, not the cause,”...