President Trump on Sunday used his Twitter platform to try and discredit James Comey and Andrew McCabe, whose FBI careers were cut short amid acrimony over the Russian-meddling probe and how the bureau handled probes into the Clinton family. Both men reportedly kept memos detailing their interactions with Mr. Trump, which could factor into Special Counsel Robert Mueller’s investigation of any ties between Russia and the Trump campaign, or fuel potential obstruction of justice charges against the president.