After WWII, the US was very concerned about the spread of commun-ISM, and made many propaganda films and papers. Unfortunately, it lead to the McCarthy witch hunts, commonly called McCarthy-ISM… The blog link you posted says this cartoon was far-fetched in 1948, but it was anything but that. The perception of communism was a very real threat.
I’m guessing this blogger was trying to use this cartoon to express his anti-Obama sentiments, which wasn’t the purpose of this cartoon.
If it walks like a duck......and quakes like a duck.....it's probably a duck.