The head of the Democratic National Committee on Friday joined calls for President Trump to cancel a scheduled meeting with Russian President Vladimir V. Putin following the indictment of 12 Russians for hacking. DNC Chairman Tom Perez said it “defies logic that Putin did not know of this” and said that Mr. Trump’s attempts to undermine Special Counsel Robert Mueller’s investigation into Russian interference in the election — which led to the new charges announced Friday against Russian intelligence officers — has hurt the nation. “President Trump should absolutely cancel this meeting with Putin,” Mr. Perez said. “Putin is not...