Tom Palmer puts it very well

From a post on McCarthyism

(It’s astonishing how the issue of the very real communist threat to liberty over a period of many decades—fortunately now behind us—has been occluded by the reckless behavior of the senator from Wisconsin. I find that when I mention in a talk that so-and-so was or is an outspoken Communist [or communist], I have to mention that I’m not red-baiting, because so-and-so actively called for establishing the dictatorship fo the proletariat and abolishing private ownership of the means of production, or was a membership of the Communist Party. A simple statement of fact is generally considered evidence of vicious “red-baiting.” The propagandists for the cause of communism did a truly brilliant job and the effects are still with us. Let’s hope that, with the USSR now dead and buried, this particular bit of dishonesty can be uncovered for what it was and is: an attempt to mask a movement for mass murder and total dictatorship as a kind of harmless lifestyle that was persecuted by fanatics whose crimes [such as denying work to intellectual thugs like the wealthy Dalton Trumbo] were far worse than anything ever contemplated by the harmless communist intellectuals, who merely wanted to liquidate much of the population and plunge the rest into a long night of tyranny and poverty.)

And, later in the comments, more bashing of Dalton Trumbo

I'd never express ill will toward the family of someone such as Dalton Trumbo; it's his personal story that's not admirable. He called in the FBI to investigate people who had written to him about his anti-war book "Johnny Got his Gun" -- after Hitler had attacked Stalin. He only brought the book out again after the Allied victory over the Axis powers, when he again became "anti-war." He's been portrayed as a principled advocate of freedom of speech, but that's not consistent with his actions; he supported freedom of speech that he thought was favorable to the USSR, and he opposed any freedom of speech that he thought was not favorable to the USSR. Needless to say, none of his family members bear any responsibility for his behavior. Nor does it excuse the clownish, disgraceful (and counter-productive) antics of Senator McCarthy.