Complex sentence: Prior to that, he was a noted New York municipal bond lawyer, director of Nixon's 1968 presidential campaign, and one of Nixon's closest personal friends; after his tenure as Attorney General, he served as director of Nixon's 1972 presidential campaign.
Split into simpler sentences: Prior to that, he had been a municipal bond lawyer, director of Nixon's 1968 presidential campaign, and one of Nixon's closest personal friends. After his tenure as Attorney General, he served as director of Nixon's 1972 presidential campaign.