The AllSides team found that Slate never includes a Right-leaning perspective on its website, making it unbalanced. Opinion pieces on Slate are clearly labeled news, making it unclear to readers what is fact and what is opinion. In its news reporting, Slate often uses subjective and emotional words.
At the time of review on Sept. 6, 2018, we noted that multiple pieces of Slate content labeled "news" were not balanced, and gave readers only a Left perspective on issues of the day. For example, that day a piece on the site claimed that the Brett Kavanaugh Supreme Court nomination is "a matter of life and death" for women — a subjective statement. Another piece claimed the Trump administration was "ignoring" rules against indefinite detention of undocumented children, when in reality the administration released documents proposing to amend them. Another Slate piece labeled "news" opened, "Donald Trump, who is somehow the president, did an interview..." AllSides determined Slate's framing of these issues and subjective language has a clear Left media bias.
According to the 2014 Pew Research study, a clear majority of Slate's audience (76%) is left-of-center.
In December 2016, Fox News published a piece titled: "BIAS ALERT: Slate switches from defense of Electoral College to calling it a tool of white supremacy."
According to Wikipedia, Slate is an "online magazine that covers current affairs, politics, and culture in the United States from a liberal perspective."
Slate is a United States-based, English language online current affairs and culture magazine created in 1996 by former New Republic editor Michael Kinsley, initially under the ownership of Microsoft as part of MSN. On 21 December 2004 it was purchased by the Washington Post Company. Since 4 June 2008 Slate has been managed by The Slate Group, an online publishing entity created by the Washington Post Company to develop and manage web-only magazines. Source: Wikipedia