Fetterman, Platner, and Communism

In the past week or two I have come across this tidbit concerning what Pennsylvania's US Senator John Fetterman claims about Maine's Senate contender expected to be the opponent of Susan Collins, Maine's Republican US Senator this fall.

Go to the 1:30 point in the video and listen:

TOP Democrat THREATENS John Fetterman on LIVE TV—Then Everything BLOWS UP in Their Face!

I am a Maine voter and yet this news interview of Fetterman is the only source I am aware of concerning this claim. What gives?