WASHINGTON (WASHINGTON POST) - A report prepared for the United States Senate that provides the most sweeping analysis yet of Russia's disinformation campaign around the 2016 election found the operation used every major social media platform to deliver words, images and videos tailored to voters' interests to help elect President Donald Trump - and worked even harder to support him while in office.
The report, a draft of which was obtained by The Washington Post, is the first to study the millions of posts provided by major technology firms to the Senate Intelligence Committee, led by Republican Senator Richard Burr of North Carolina, its chairman, and Mr Mark Warner of Virginia, its ranking Democrat.
The bipartisan panel hasn't said if it endorses the findings. It plans to release it publicly along with another study later this week.
The research - by Oxford University's Computational Propaganda Project and Graphika, a network analysis firm - offers new details on how Russians working at the Internet Research Agency, which US officials have charged with criminal offences for meddling in the 2016 campaign, sliced Americans into key interest groups for the purpose of targeting messages. These efforts shifted over time, peaking at key political moments, such as presidential debates or party conventions, the report found.
The data sets used by the researchers were provided by Facebook, Twitter and Google and covered several years up to mid-2017, when the social media companies cracked down on the known Russian accounts.
The report, which also analysed data separately provided to House intelligence committee members, contains no information on more recent political moments, such as November's midterm election.
"What is clear is that all of the messaging clearly sought to benefit the Republican Party-and specifically Donald Trump," the report says. "Trump is mentioned most in campaigns targeting conservatives and right-wing voters, where the messaging encouraged these groups to support his campaign. The main groups that could challenge Trump were then provided messaging that sought to confuse, distract and ultimately discourage members from voting."
Representatives for Mr Burr and Mr Warner declined to comment.
The new report offers the latest evidence that Russian agents sought to help Mr Trump win the White House. Democrats and Republicans on the panel previously studied the US intelligence community's 2017 finding that Moscow aimed to assist Mr Trump, and in July, they said investigators had come to the correct conclusion. Despite their work, some Republicans on Capitol Hill continue to doubt the nature of Russia's meddling in the last presidential election.
The Russians aimed particular energy at activating conservatives on issues such as gun rights and immigration, while sapping the political clout of left-leaning African-American voters by undermining their faith in elections and spreading misleading information about how to vote. Many other groups - Latinos, Muslims, Christians, gay men and women, liberals, southerners, veterans - got at least some attention from Russians operating thousands of social media accounts.
The report also offered some of the first detailed analyses of the role played by YouTube, which belongs to Google, and Instagram in the Russian campaign, as well as anecdotes on how Russians used other social media platforms - Google+, Tumblr and Pinterest - that have gotten relatively little scrutiny. The Russian effort also used email accounts from Yahoo, Microsoft's Hotmail service and Google's Gmail.
The authors, while reliant on data provided by technology companies, also highlighted their "belated and uncoordinated response" to the disinformation campaign and, once it was discovered, criticised the companies for not sharing more with investigators. The authors urged the companies in the future to provide data in "meaningful and constructive" ways.
Facebook, for example, provided the Senate with copies of posts from 81 Facebook "Pages" and information on 76 accounts used to purchase ads but did not share the posts from other user accounts run by the IRA, the report says. Twitter, meanwhile, has made it challenging for outside researchers to collect and analyse data on its platform through its public feed, the researchers said.
Google submitted information in an especially difficult way for the researchers to handle, providing content such as YouTube videos but not the related data that would have allowed a full analysis. The YouTube information was so hard for the researchers to study, they wrote, they instead tracked the links to its videos from other sites in hopes of better understanding YouTube's role in the Russian effort.
Facebook and Google didn't immediately respond to requests for comment. In a statement, Twitter stressed that it had made "significant strides" since the 2016 election to harden its digital defences, including the release of a repository of the tweets that Russian agents previously sent so researchers can review them.
"Our singular focus is to improve the health of the public conversation on our platform, and protecting the integrity of elections is an important aspect of that mission," the company added.