By MICHELLE L. PRICE and ZEKE MILLER WASHINGTON — Kamala Harris and Donald Trump will meet for the first time face-to-face Tuesday night for perhaps their only debate, a high-pressure opportunity to showcase their starkly different visions for the country after a tumultuous campaign summer. The event, at 9 p.m. Eastern in Philadelphia, will offer Americans their most detailed look at a campaign that’s dramatically changed since the last debate in June.