President TrumpDonald John TrumpFormer National Security Adviser John Bolton gets book deal: report Trump administration proposes fee for asylum applications, spike in other immigration fees Biden expresses shock that Trump considers attending Russia May Day event MORE tore into the House’s impeachment investigation in an early Saturday morning tweetstorm as the inquiry is set to enter a new, public phase next week. 

He retweeted 17 messages in roughly an hour hammering Democrats over the probe, including a handful specifically going after some witnesses who have already testified behind closed doors.

“STU: ‘The #democrats know they can't remove @realDonaldTrump from office but they'll go ahead with the #impeachment process anyways because they detest him!’” Fox Business host Stuart Varney said in a post retweeted by Trump.

“A total and complete circus! Just petty politicians trying to undo @realDonaldTrump's victory. Now, if only the ringleaders would let Congress get back to work on behalf of the American people,” read a post from Rep. Roger MarshallRoger W. MarshallTrump tears into impeachment probe, witnesses in early Twitter spree Republicans storm closed-door hearing to protest impeachment inquiry Conservative Republicans unveil latest ObamaCare replacement plan MORE (R-Kan.) that the president highlighted.

The House’s impeachment inquiry was launched in September amid Democratic concerns that Trump leveraged $400 million in military aid to pressure Ukrainian President Volodymyr Zelensky to publicly open an investigation into unfounded corruption allegations against former Vice President Joe BidenJoe BidenDecember Democratic debate venue switched to Loyola Marymount University Biden expresses shock that Trump considers attending Russia May Day event Strategists say Warren 'Medicare for All' plan could appeal to centrists MORE, a top political rival, and his son.

The White House has repeatedly blasted the House investigation as a "witch hunt" and decried Democrats' efforts as "unhinged" after they voted to formalize the inquiry late last month. 

Democrats have countered the president has abused his oath of office by seeking to involve foreign nations in U.S. domestic politics after publicizing testimony from several witnesses who said there was a quid pro quo surrounding Trump's dealings with Ukraine

Trump has repeatedly railed against the inquiry on the campaign trail, accusing Democrats of trying to reverse the results of the 2016 presidential race. However, he went a step further Saturday, retweeting messages specifically linked to witnesses who have already testified in the probe.

“The Dems/media are desperately relying on Taylor as their star witness to show there was an impeachable offense of quid pro quo. Aside from the fact he admits he has no idea what quid pro quo even means, Taylor also admitted to me his claims aren't based on 1st hand knowledge,” Rep. Lee ZeldinLee ZeldinTrump tears into impeachment probe, witnesses in early Twitter spree White House doubles down on 'no quid pro quo' Lobbying world MORE (R-N.Y.) said in a tweet about William Taylor, who serves as the chargé d’affaires for Ukraine and testified that he believed there was a quid pro quo with Ukraine, that was retweeted by Trump.

The president's Saturday morning tweetstorm underscores the extent to which the House’s impeachment investigation has consumed his attention, leading some allies to worry that his focus should be more equally shared between the probe and his legislative priorities. 

“Then they all wonder why they don't get gun legislation done, then they wonder why they don’t get drug prices lowered,” Trump said in September. “Because all they do is talk nonsense. No more infrastructure bills, no more anything.”