(CN) - Members of Congress may be reinforcing partisan social media bubbles with the news links they share on Facebook, a new Pew Research Center report says.
The analysis of lawmakers' posts released Monday looked at the links members of the House and Senate shared in nearly a half million posts between January 2015 and July 2017.
Pew researchers found that about 48 percent of those links were to national news outlets preferred by members of one political party or another.
In 5 percent of those cases, the news links pointed to outlets that were exclusively linked to by members of one political party.
For example, the researchers note that Breitbart News was linked to nearly 700 times by Republican lawmakers during the study period, and zero times by their Democratic colleagues.
Meanwhile congressional Democrats share links to Huffington Post articles 1,100 times, while Republican share HuffPo links just 89 times during the period.
Republican lawmakers are also far less likely than their Democratic colleagues to share news links from NPR and the New York Times.
However, the analysis found that some news outlets had about equal appeal to Democrats and Republicans. These included the Washington Post, the Hill -- which covers Capitol Hill -- and CNN.
An earlier Pew Research Center report found that people who follow members of Congress on Facebook also play an important role in disseminating news on social media. The new report elaborates on those findings.
According to Monday's analysis, Facebook audiences re-shared news stories from roughly 22 percent more often when it came from an outlet that reflected their political leaning, rather than a news organization that falls in the middle of the political spectrum.
After the election of President Donald Trump, Democrats in Congress became twice as likely to share Facebook posts that included links to national news stories (8 percent to 16 percent), while Republicans became slightly less likely to share posts linking to national news stories (9 percent to 8 percent).
Pew researchers also discovered that Facebook users were far more likely to use the “angry” emoji button in response to posts congressional Democrats shared after Trump was elected.
Between the election and July, 18 percent of all reactions to Democratic lawmakers’ news links were “angry,” compared to 5 percent before the election.
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