President Donald Trump on Tuesday said special counsel Robert Mueller's team would be "meddling" in the fall midterm elections — his latest evidence-free charge against the members of law enforcement charged with investigating Russian interference in the 2016 election.

"The 13 Angry Democrats (plus people who worked 8 years for Obama) working on the rigged Russia Witch Hunt, will be MEDDLING with the mid-term elections, especially now that Republicans (stay tough!) are taking the lead in Polls," Trump tweeted.

The 13 Angry Democrats (plus people who worked 8 years for Obama) working on the rigged Russia Witch Hunt, will be MEDDLING with the mid-term elections, especially now that Republicans (stay tough!) are taking the lead in Polls. There was no Collusion, except by the Democrats! — Donald J. Trump (@realDonaldTrump) May 29, 2018

"There was no Collusion, except by the Democrats!" Trump added.

In a series of other tweets, Trump also questioned why Mueller’s team wasn’t investigating Hillary Clinton’s presidential campaign and "Clinton/Russia/FBI/Justice/Obama/Comey/Lynch etc."

“It’s a Rigged Witch Hunt, that’s why! Ask them if they enjoyed her after election celebration!” he wrote.

Why aren’t the 13 Angry and heavily conflicted Democrats investigating the totally Crooked Campaign of totally Crooked Hillary Clinton. It’s a Rigged Witch Hunt, that’s why! Ask them if they enjoyed her after election celebration! — Donald J. Trump (@realDonaldTrump) May 29, 2018

Sorry, I’ve got to start focusing my energy on North Korea Nuclear, bad Trade Deals, VA Choice, the Economy, rebuilding the Military, and so much more, and not on the Rigged Russia Witch Hunt that should be investigating Clinton/Russia/FBI/Justice/Obama/Comey/Lynch etc. — Donald J. Trump (@realDonaldTrump) May 29, 2018

Trump has repeatedly claimed Mueller’s investigation is a partisan effort to undermine his administration, which he often calls a "witch hunt."

In recent weeks, he has repeatedly attacked Mueller’s team — which he has at times dubbed the "13 angry Democrats" — and has accused the Department of Justice of having improperly inserted a “spy” inside his campaign.

Former intelligence community officials have forcefully pushed back on the president's claims and defended the FBI's reported use of an informant in its Russia investigation. After a classified Justice Department briefing attended by a bipartisan group of top lawmakers last week, Rep. Adam Schiff, D-Calif., said there "is no evidence to support any allegation that the FBI, or any intelligence agency, placed a spy in the Trump campaign or otherwise failed to follow appropriate procedures and protocols."

Since Mueller's appointment, nearly 20 individuals have been charged with crimes, including five who pleaded guilty (among them Michael Flynn, Trump's former national security adviser) and 13 Russian nationals.