Possible Clues:

• Telegraph protecting main Conservative upstart
• Know-all may appear to be perceptive over the port
• Person with an affectation of wisdom
• Message about hopeless case in smart Aleck
• Smart-alecky know-it-all
• Professor of knowledge we care about is accepted
• Crew I misdirected across part of ocean, as self-styled expert
• Telegram about marine initially confounded smart alec
• Know-it-all describes one of those in 4 down with land
• Clever Dick's telegram closes case that's resolved