Political journalists will remember the evening well.

It was around 8:45 p.m. on Jan. 20, before President Obama gave the State of the Union address, when the White House released the full text of his speech on a three-year-old Web site called Medium.

The move broke convention, and the Washington press was surprised. Many reporters were afraid to admit their ignorance about the site. Obama aides could barely contain their delight at, in the words of White House Chief Digital Officer Jason Goldman, “changing a SOTU tradition forever.”

Since then, Medium has muscled its way to the front of the line as the blog platform for Washington leaders who want to put a fresh veneer on their messaging. After heavy use by the Obama White House, the San Francisco start-up has ambitions to be a player in the 2016 political debate by becoming the venue of choice for candidates to bypass the mainstream media and air their thoughts online.

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Anyone can write for Medium, which is designed to merge the utility of Blogger with the social experience and immediacy of Twitter. An April story in Wired magazine pegged its monthly unique visitors at a healthy 25 million. The site does not publicly release traffic figures, though one official called the Wired figure “old.”

But the company has higher aspirations than hosting run-of-the-mill blog posts from unknown writers. In a 2014 job listing for its first Washington, D.C.-based position, Medium pitched itself as the op-ed page for the social media era, a utopian forum of writing and debate where leaders could bring thoughtfulness and order to the news cycle.

Whether this vision is realistic or simply a marketing pitch is up for debate. To some journalists, Medium sounds a lot like a way for leaders to gain the aura of being culturally and technologically dialed in while retaining tight control over their image, usually through the work of their aides.

The company doesn’t see it this way. Medium’s clean and interactive design can offer readers a more edifying reading experience than newspapers, argued Matt Higginson, the site’s sole employee in Washington.

“I can certainly understand why a policymaker or a political voice would want to publish in the New York Times or the Washington Post op-ed pages, but those are pretty limiting,” the former Sen. Harry M. Reid (D-Nev.) aide said in an interview.

“You see back-and-forth on Medium that you cannot get other places,” he said. “You might see some similar exchanges on Twitter, but they are limited by character length. Medium is designed as a way to continue those conversations in longer form.”

While not a source for daily news, Medium has hosted several newsworthy posts since the beginning of the year. Mitt Romney used the site to announce that he would not run for president in 2016. Hillary Clinton’s campaign used it to rebut allegations about kickbacks at the Clinton Foundation contained in the book “Clinton Cash” by Peter Schweizer.

Just as many times, however, the site has been the butt of jokes among professional reporters.  While some of Medium’s writers are paid professionals, a casual visitor is just as likely to encounter a press release (“This Is Not The End Of The Fight Against ObamaCare” via Jeb Bush) as a listicle (“8 Things Every Person Should Do Before 8 A.M.”) or a self-help column (“Why It Helps To Be Hopeless”). The site is a dense jungle of topics and styles, and it grows by hundreds of new posts every day.

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The lack of editorial vision can give the impression that Medium is a dustbin for stories that would not be published elsewhere. “All you other editors rejected Obama’s submission too?” Atlantic staff writer David A. Graham tweeted in October when the White House published its first post.

Higginson spends his days pitching Medium to Capitol Hill, top political campaigns, interest groups and think tanks. All told, there are more than 140 high-profile political figures on Medium, including 87 sitting members of Congress, he said.

A June 10 story by Sen. Ron Wyden (D-Ore.) criticizing NSA surveillance shows how lawmakers use Medium.

“We were looking for a platform where we could get the message out quickly, first of all, and without any kind of intermediary,” said Keith Chu, a Wyden spokesman.

“Medium is obviously great for issues where you have a younger, more savvy audience,” he said. “It also allowed us to imbed video and get into Sen. Wyden’s history in a way that you just can’t with a newspaper op-ed.”

A key proponent for the site is former Obama adviser Dan Pfeiffer. Not only was he instrumental in releasing the State of the Union text on the site, but he also wrote a farewell post on Medium when he left the White House in March.

With Pfeiffer’s encouragement, Medium has become a go-to place for the White House to publish soft news and commentary, another way it uses social media to circumvent the traditional media. The site offers a stunning visual display that lends itself to the polished, often tightly controlled photo record of the Obama White House. One recent post offered a tribute to Vice President Biden’s late son, Beau, with a series of family photos. Even a recent post unveiling the Obama state china turns a banal topic into something engaging.

Medium, the brainchild of tech prodigy Evan “Ev” Williams, is designed to elevate stories that readers are viewing for longer periods of time and lower those that generate less attention. Like a more erudite BuzzFeed, it highlights its most engaging content (measured via Total Time Reading, or TTR) and buries much of the rest.

Under this model, light, grabby stories can still float to the top, challenging Medium’s desired image as a serious forum for debate online.  But Higginson said there is room for everything on the site, and that besides, a measure of levity can encourage politicians to abandon their typical “buttoned-up, boring, milquetoast” communication style. On Medium, he said, leaders can become “authentic.”

“Maybe it sounds naive, but I hope we can get to a place where words matter a little bit more and authenticity is valued,” he said. “It’s not something to try and fake but it’s something to try and be.”

Medium has not yet achieved the status of a destination site in Washington, and its adoption is hardly universal among political candidates and the congressional rank-and-file. Even the White House, despite its enthusiasm, remains digitally promiscuous when it comes to releasing news.

But at a time of social media saturation in politics — not to mention serious Silicon Valley fever in Washington — Medium’s pitch is simple and effective. The site is slick, message-driven, ostensibly interested in substance and socially networked to the hilt. In other words, it pushes all of Washington’s buttons.