Nixon got things done. McCarthy simply (a) grandstanded and (b) made ALL anti-communists look like grandstanders.
The "right way" is as follows:
1. Don't make allegations unless you're dead certain your right. McCarthy FREQUENTLY violated this rule.
2. Don't make up figures (the ever-shifting number of "card-carrying Communists" in the State Department, for example).
3. Don't wave your laundry list (literally) during a speech and say "I have here a list of Communists in..." Eventually, the fact that you're just waving a list that has two shirts, three pairs of pants, and six boxers will get out.
4. Don't use people of dubious ethics (Roy Cohn, Bobby Kennedy) to do "dirty work." If the work's too dirty for you to do it yourself, it shouldn't be done.
5. Remember that you are supposed to be a good guy. Act like one.