How would Donald Trump know whether or not Tulsi Gabbard or Jill Stein are a Russian asset when he claims not to know either of them them?

In the middle of his bonkers interview with Sean Hannity last night, Trump made this odd declaration:

TRUMP: Now I don't know Jill Stein. I know her as an environmentalist. OK, and probably a good woman. The last thing she is, is a Russian asset. I don't know Tulsi Gabbard. But I know one thing. She's not an asset of Russia.

He was referring to Hillary Clinton's recent allegation that the two are Russian assets. (Bizarrely, Gabbard did not deny the allegation when she was asked about it by Tucker Carlson last week.)

How would Trump know? Does he have some inside knowledge about who is a Russian asset? Predictably, Hannity did not ask.

Watch Trump’s peculiar claim below, from the October 21, 2019 Hannity. The remark occurs at about 5:45.