In private, Trump has often expressed different worries about the 2020 candidate.

In the past two months, the president has repeatedly asked advisers, in and out of the White House, about how Sanders polls, or would likely perform, in critical battleground states, specifically Pennsylvania, according to two people who’ve independently heard him ask about it. At times, Trump has asked about Sanders’ prospects even in the absence of a current public or internal poll on the matter.

It’s hardly the first time Trump has talked to his friends and top lieutenants about Sanders’ potential formidability heading into an election year. As The Daily Beast reported last year, Trump had on multiple occasions told longtime associates and Republican donors that running against “socialism” in 2020 may not be “so easy” due to its populist appeal. At a private event with donors late last year, the president said, according to a source in the room, that “you can have someone who loves Trump, but many people love free stuff, too,” adding that if Sanders or other “socialist” candidates promise U.S. voters—particularly young voters—that they will cancel their debt, “that’s a tough one [to run against].”