Someone who supports Palestine and is against the US is not automatically a Tankie. But if this person at the same time makes excuses for the Russian invasion or argues that Taiwan belongs to China, then they are.
Hypocrisy (lying / arguing in bad faith) is exactly what makes the difference between a leftist and a Tankie.
It all boils down to the question if we should care about people arguing in bad faith.
Carlson proved to be Putin's mouthpiece, everything he says follows an agenda, which is, as mentioned in the article, to divide the US.
Does it matter that he and a lot of people on social media just play pretend because they want to hurt Bidens chances of reelection?
I think it should be allowed to be pointed out, even though they're not wrong. They just don't care about Palestinians. For Carlson at least that much is obvious.