When the right wing tries to demonize the left by associating them with socialists or communists then their argument is instantly voided and they lose the discussion. Works in the same manner as Godwin's Law.
"The left wing loons in this country have been overtly pushing for socialism for decades. Back in 1961 Ronald Reagan warned us about socialized medicine as the first step to a complete socialist nation where all liberty and freedom will be destroyed."
"You've just lost this debate by Forney's Law. Any further points you make now hold no weight - your credibility is lost. Good day to you."