Rep. Michael Capuano was first elected to Congress in 1998. In the years since, he hasn’t had a serious primary challenger. But 2018 isn’t an ordinary election year, and he finds himself in a competitive race with a formidable opponent for his seat representing Massachusetts’ 7th district. Capuano’s message to voters is this: His voting record is solidly progressive, he has stood up to the Trump administration and his seniority in the House of Representatives means he can be a more powerful voice on behalf of his district. WGBH News spent time with the congressman in the run-up to the Sept. 4 primary. This is the story of a day in his campaign, in pictures.