The vast majority of McCarthy's victims were not accused of any crime (other than Contempt of Congress), but his groundless accusations against them were enough to cost many of them their careers and to cause many more to lose years of their careers. And his fraudulent claims and relentless defamation were carried out in public. On the other hand, Trump et al are being accused of specific, criminal acts  - accusations backed by a lot more than Ol' Joe's infamous blank book. 
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Paul Manafort wasn't just "employed by" the Trump campaign, he was the Campaign Chairman. And it was more than "a few months". And some of those crimes in the indictment are a LOT more recent than "ten years earlier." As in, up to and including things he did WHILE he was Chairman.