The takeaway point: it was so short. No, not McCarthy himself, but the age of McCarthy, his time on the world stage. It lasted from February 9,1950, the day of the notorious "Wheeling Speech" until December 2, 1954, the day of the Senate censure vote. That's a little under five years, bracketing the Korean War and about coterminous with The Complete Peanuts 1950-1954 Box Set--little more than a third as long as the nightmare of Adolph Hitler, well less than the time between now and Mission Accomplished in Iraq.
And at the end, there wasn't all that much to show for it. As many have said, as Oshinksy says, he never uncovered a Communist--perhaps never even a "security risk," for however elastic that term may be, it seems likely that every single person whom McCarthy outed either (a) was already identified; or (b) would have been identified in due course. He ruined a few lives, of course and disrupted countless others, but hey you know what they say about eggs and omelettes. Beyond that, it is remarkable how little he left behind. Others--notably Richard Nixon, who scored with Alger Hiss, and even more the mostly forgotten, vastly underrated, Pat McCarren--made a far more lasting impact on our lives.
The other amazing fact is that he really didn’t have any particular talents at all, except perhaps an eye for weakness, a knack for spotting easy targets that other people might not have noticed as easy (the old judge he knocked off in his first race in Wisconsin; Senator Robert LaFollette Jr.; Senator Millard Tydings; Robert Stevens of the Army). Except for that, he really was what Herblock pretended to caricature: a coarse and vulgar bully.
Comparing him with other public menaces is enough to put him in perspective. He's been called an "American Hitler," but this trivializers Hitler: McCarthy had nothing like Hitler's manic, obsessive vision. Comparing with Mussolini is trickier: granted that Mussolini brought down a government, still it is important to remember that Mussolini's Italy was harldy a state at all--only half a century old, and the Pope always telling them that evading the taxes of the secular authorities was not a sin. It's tempting to speculate that if Mussolini had met any serious resistance, he would have caved, too.
Yes, resistance. Granted, reading about the GOP in the 50s is enough to remind you that (aside form McCarthy), they had quite an ample supply of fools, bullies and paranoid nutcakes. I think they may also have had a larger stock of civic-minded gentlemen, though this is harder to say (Arthur Watkins and Margaret Chase Smith probably count; anonymous characters like Norris Cotton; probably Ralph Flanders though he may be a closer case). In any evengt, those who passed as gentlemen at last did what they were supposed to do.
Except that in a sense you could say that McCarthy was the ultimate author of his own misfortune. He never had an agenda, beyond beating up on the vulnerable. By the time of the censure vote he had already begun to drink himself to death. It was only a matter of time before he finished the job.