Bernie Sanders bore down on Donald Trump’s economic agenda in a series of tweets on Friday morning, calling him “the poster child of failed trade policies.”

The social media take-down began with Sanders posting a link to a Washington Post story from earlier this week, which revealed how a “little-noticed provision in Donald Trump’s tax reform plan has the potential to deliver a large tax cut to companies in the Republican presidential nominee’s vast business empire.”

Then Sanders got on a roll, eviscerating Trump’s positions on trade and taxes:

As Politico notes, “Trump has repeatedly used Sanders’ attack line questioning Clinton’s judgment on the trail and consistently claimed that Sanders’ supporters will back his campaign because of where he stands on trade.”

Friday’s tweetstorm appears to be part of Sanders’ ongoing push to ensure that does not happen.