Slightly OT, but I'm not sure that Powell lacked a capacity for hard work - he was famous for his work rate when a student, and his two biographies suggest that his civil servants were impressed (and sometimes daunted) with his ability to get through long, tedious memoranda and where appropriate present his alternative view to the civil service within the space of an evening's work. In fact, his capacity for work is part of what made him slightly odd...
(BTW he was sacked from the Shadow Cabinet after the speech (he was shadow Sec of State for Defence rather than sent to NI), and the 'Rivers of Blood' speech - not that the phrase 'rivers of blood' appeared in it - was made at the Midland Hotel in Birmingham, rather than in the Commons.)