President Trump said Friday morning that the protesters cornering senators in elevators on Capitol Hill to oppose the confirmation of Supreme Court nominee Brett Kavanaugh are paid professionals meant to make lawmakers look bad, as proven by their “professionally made identical signs.”

“The very rude elevator screamers are paid professionals only looking to make Senators look bad. Don’t fall for it!” Trump posted to Twitter Friday morning. “Also, look at all of the professionally made identical signs. Paid for by Soros and others. These are not signs made in the basement from love! #Troublemakers”

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Trump claimed the protesters are being paid by George Soros, among others, in what was his first Twitter reference to the billionaire investor.

Trump's tweet came after Senate Judiciary Committee Chairman Chuck Grassley, R-Iowa mentioned Soros earlier in the day in an appearance on Fox Business.

Asked by host Maria Bartiromo about the possibility that Soros-funded organizations were paying the protesters, Grassley replied that he is inclined to believe it’s true.

"I have heard so many people believe that. I tend to believe it," Grassley said. “I believe it fits into his attack mold that he has, and how he uses his billions and billions of resources.”

[More: Orrin Hatch ignites anti-Kavanaugh protester anger with 'grow up' comment]

Grassley said some lawmakers have promoted this “incivility in American society,” by advocating for people to get in the face of members of the cabinet when they disagree with them.

Protests descended on Capitol Hill throughout the confirmation process of Supreme Court nominee Brett Kavanaugh after women went public with sexual assault allegations against him.

Several have made their way into elevators with senators to voice their disapproval of Kavanaugh and share their personal experiences with sexual assault.

Ford and Kavanaugh testified before the Senate Judiciary Committee last Thursday and the panel voted along party lines last Friday to recommend Kavanaugh’s confirmation to the Senate floor.

Senate Majority Leader Mitch McConnell, R-Ky., scheduled a vote to end debate on Kavanaugh's nomination for Friday morning, with a final confirmation vote eyed for Saturday or Sunday.