WASHINGTON — In his first formal response to impeachment charges, President Donald Trump misrepresented the testimony of a key witness who described an exchange of favors in the Ukraine matter. The claim marked a week of frequent exaggeration and distortion by the president heading into the opening statements of his impeachment trial. Just as his tax cuts are far from the biggest in history, the economy isn’t the best ever and his election victory in 2016 was no landslide of historic proportions, Trump’s two trade deals don’t stand atop the field of presidential endeavors. One is a partial settlement of...