Okay, this cartoon is about as subtle as a brick. Anytime you invoke the memory of Joseph McCarthy, you will appear heavy-handed. But old Joe lacked subtlety, too, and look how effective he was.
Sometimes, the situation calls for directness, especially if you feel we're poised on the edge of a slippery slope.
Judging from the email I get, McCarthy still has a lot of admirers out there, or he would if they knew who he was. The nation's moved on, though. There are no longer any Communists hiding under the bed. Now, we call 'em Liberals. Those who do remember Sen. McCarthy fondly will take the cartoon at face value, so no harm, no foul.