It is simple
The USA political establishment thrives on promoting fear of the international boogie man
For years it was "the Yellow peril" then "the pinko commie" threat, more recently it was "the Gay agenda", then "the trans" agenda, they promoted hate of "the other".
However with the rise of anti-racism, anti-sexism, religiophobia, people have been placed in the situation where hating makes the hater the villian of the piece not the protective hero.
Afghanistan was a prime example of this, for years hating the Taliban was an idea boogie man, different religion, different skin tone, different culture, BEARDS, etc. But suddenly hating the middle eastern threat was all wrong, it was racist, it was religious prejudice, it was cultural hatred. One phobia was set against another, Yes the A-Rab as the US like to call him was sexist BUT he is also a brown person and that makes you a racist if you call him out on it, and so on and it simply became too much trouble.
BUT to go back to the old favourite "The Pinko, commie, red under the bed, rubal loving Russian bastard" and all that goes away.
Nostalgia value, lots of us remember the cold war, damn most red necks don't even know Russia and the Soviet union are still not the same thing. Lots of us grew up hating AND FEARING the Russians and long for those uncomplicated good ole days.
They are white, so no race problem
They are mostly Christian (But not PROPER Christian)
They are atheist so no religious problems, but still a deep mistrust of the godless heathen.
They mistreat brown people much worse than we do
They collaborate with the sneaky inscrutable Chinese
They don't speak ENGLISH so they could be saying anything behind your back
They eat funny food
They put Bears on Unicycles
They have atomic bombs
They live were it is always snowing , so they want out warm and pleasant lands
The Klingons were based on them
And you just cannot trust them!!!!
Even woke people are frightened of them and have no reason to complain if other people do to

BINGO and we have a winner!