Hillary Clinton (Yahoo News photo Illustration; photo: Steve Parsons/PA via AP)

SAN FRANCISCO — Hillary Clinton’s campaign was blindsided by the sophistication and breadth of Russia’s social media efforts to subvert her 2016 presidential bid and promote Donald Trump’s candidacy, former senior policy adviser Jake Sullivan said in an interview.

“We didn’t come to understand this was even going on until very late in the day, and it wasn’t until the closing days of the election that we started to realize that maybe something was happening,” Sullivan told Grant Burningham, host of the Yahoo News podcast “Bots & Ballots.” “And it really wasn’t until after the election that we came to understand the full scope and scale of the Russian effort and how the social media aspect of it was amplifying and driving the hacked and leaked documents aspect of it.”

Sullivan said that while the Clinton campaign was aware of Russian attempts to hack its servers, it initially wrote off those efforts as similar to the ones Moscow had reportedly launched to penetrate the campaigns of candidates John McCain and Barack Obama.

“It really wasn’t until the documents started coming out around the Democratic National Convention in July that we realized there was a different game going on,” Sullivan said. “There was something else afoot.”

Download or subscribe on iTunes: “Bots & Ballots” by Yahoo News

Sullivan said “the effort to weaponize the information, that’s something we hadn’t seen before,” and admits that “we weren’t quite ready for it.”

Listen to Sullivan’s full interview with Burningham here.

_____

More “Bots & Ballots” episodes from Yahoo News: