Donald Trump Jr.Donald (Don) John TrumpDonald Trump Jr. says critics are 'subverting will of the people' The Hill's Morning Report - Fallout from day one of Trump impeachment hearing Trump Jr's 'Triggered' debuts at No. 1 on NY Times bestseller list MORE took to Twitter on Sunday to troll House Intelligence Committee Chairman Adam SchiffAdam Bennett SchiffTrump on Schiff: 'He will not make the LSU football team' Trump knocks testimony from 'Never Trumpers' at Louisiana rally Johnson opens door to subpoenaing whistleblower, Schiff, Bidens MORE (D-Calif.) hours after Attorney General William Barr delivered a summary of special counsel Robert MuellerRobert (Bob) Swan MuellerSpeier says impeachment inquiry shows 'very strong case of bribery' by Trump Gowdy: I '100 percent' still believe public congressional hearings are 'a circus' Comey: Mueller 'didn't succeed in his mission because there was inadequate transparency' MORE’s investigation to Congress.

As lawmakers from both sides of the aisle reacted following Barr’s summary of Mueller’s lengthy investigation into collusion between the Trump campaign and Russia to interfere in the 2016 election, Trump Jr. knocked Schiff for remaining quiet.

“Has anyone heard from slimy Adam #fullofschiff Schiff today?” Trump Jr. wrote in a post on Twitter Sunday evening. “I mean it must be embarrassing to have have spent the last 2 years as the leader of the tinfoil hat brigade and have it all come crashing down so quick.”

Trump Jr. borrowed the “full of Schiff” reference from his father. President TrumpDonald John TrumpButtigieg surges ahead of Iowa caucuses Biden leads among Latino Democrats in Texas, California Kavanaugh hailed by conservative gathering in first public speech since confirmation MORE has consistently ripped the California lawmaker, who is leading a congressional investigation into Trump.


Trump’s son added that he is “legitimately concerned for his mental state,” referring to Schiff.

On Sunday morning, before Barr delivered his letter to Congress, Schiff said Congress would have to consider impeaching Trump if Mueller’s report found “overwhelming evidence of criminality” on Trump's part.

According to Barr’s letter, which summarized the conclusions from Mueller’s investigation, there was no evidence of collusion between the Trump campaign and Russia to interfere in the 2016 election.

The letter says that Mueller did not make a conclusion as to whether Trump obstructed justice in the investigation of Russia's election interference, though Barr and Deputy Attorney General Rod RosensteinRod RosensteinDemocrats ask judge to force McGahn to comply with subpoena Democrats ask court to force DOJ's hand on Mueller grand jury materials Washington celebrates diplomacy — and baseball — at Meridian Ball MORE decided they would not pursue an obstruction of justice charge against Trump.