The former Fox News anchor tweeted the news of her departure from MSNBC, without providing additional details. Earlier this month, NBC Chairman Andy Lack said that the show wasn't "breaking out" but that he had patience. Sources tell Vanity Fair that the network's chief legal correspondent and weekend host, Ari Melber, will replace Van Susteren in the interim at 6 p.m.

Why it matters: MSNBC hired Van Susteren and her former colleague Megan Kelly from Fox in an attempt to lure a broader, more moderate audience after Trump's election. But neither have created as much audience buzz as Rachel Maddow, one of MSNBC's most progressive personalities, who is leading the network to record primetime viewership.