Democratic presidential candidate Hillary Clinton shakes hands with Demi Gibson, who works the order counter at Hawkins House of Burgers in Watts, Calif., on Monday. (Mike Blake/Reuters)

BARRING A truly extraordinary turn of events, the seemingly endless presidential primary season will conclude Tuesday night with Hillary Clinton as the presumptive Democratic nominee. She and her primary rival, Sen. Bernie Sanders (I-Vt.), deserve credit for competing largely on issues rather than insults. From here, she will have to contend with a Republican opponent, Donald Trump, who has sent every signal that he will run a campaign that is entirely disrespectful — of her personally, of the truth, of minority groups, of the media and of a variety of basic democratic norms.

As her recent speech attacking Mr. Trump on foreign policy showed, Ms. Clinton will argue that she is steady and reasonable where Mr. Trump is temperamental and unhinged — and she will have plenty of reasons and opportunities to argue that he is unfit to be president. Yet if she is going to be the candidate of dignity and political responsibility, she will have to do some things differently if she does not also want to be the candidate of rank hypocrisy.

One of the many political norms that Mr. Trump has set about eroding is transparency, with his fidelity to certain lies and his refusal to release his tax returns, despite decades of contrary precedent. Ms. Clinton has released a trove of tax records but for months has declined to honor another essential expectation of the nation’s leaders and would-be leaders: She has not held a real news conference since December.

In response to criticism of this inaccessibility, Ms. Clinton says she has offered some 300 personal interviews since her last news conference, and her campaign points out that she has held a handful of short, informal “gaggles” with the traveling press this year. Neither is a reasonable substitute for regularly facing the media. Candidates are less likely to face wide-ranging and tough questions and follow-ups in carefully managed interviews, where time is often limited and there is usually only one interlocutor, than they are from a room full of reporters for an extended period of time.

Ms. Clinton may calculate that holding news conferences is not in her political interest. In the early days of her campaign, some of her lowest moments came during freewheeling exchanges with the press corps, such as when she lamely attempted to joke her way out of answering a question about her State Department emails. But news conferences are not a frill to be jettisoned out of political calculation. If Ms. Clinton is unavailable to legitimate questioning now, what hope would there be once she is in office? Mr. Trump’s irresponsibility does not give her a pass to ignore the legitimate demands of democratic transparency.