yes you need a squeaky clean image to succeed, therefore he should quit smoking and other habits... at least overtly... at least for the duration of his Presidential campaign and possible tenure as the Commander in Chief.
the one thing that irks me... whether it's done by liberals or conservatives, is to defame a person for something they did in the past.
of course, if it's a crime, then you should look past it. but something trivial such as a bad habit, or even dating someone unsavory... as long as the politician is currently reformed and doing everythin gexpected of a civil servant, why bring out his/her past record?
stop focusing on the past. focus on the future.