Amber made a very good point.
As someone who is in a similar situation...highly ambitious and highly private as a person...
So how I deal with it...I know who I am, I am not ashamed of what I do, I don't think that indulging into BDSM is anything bad as such.......I am very careful about sharing my picture, very careful about people I interact with and careful to the point of paranoid about who I play with.
Don't play in public or at least be extra extra careful about who and where, avoid situations that could result in headlines containing words "money" and "favor", avoid underage participants, married ones...
So if it ever came to..."We've heard from several sources that you use to go to BDSM clubs. Is that true? Are you a sadist? Masochist? We have pictures of you at the club having a drink with a Dominatrix. Please explain.".....my answer would be "Yeah, so what, your point being? Now if we could concentrate on business at hand..." and make a mental note to sue them for invasion of privacy.
But I should point out that I am from Europe and we look at things differently. Private lives of politicians are not nearly as big a deal here as they seem to be in US, and even when they do come to attention, they don't play much (if any) importance in the voting booth.
There was a big scandal here this year involving Max Mosley (the president of FIA, a governing body for Formula One and other international motorsports)...nobody even blinked about BDSM aspects of it, the point of contention was that he used prostitutes and Nazi insignia in play (a sensitive matter due to his parents close ties to Hitler) and that his wife of 30 years knew nothing about it. Anyway he kept his job, sued the newspapers, won the (landmark) case...and few moths later it has already almost faded from public memory.
So if the worst happens just do as those gay pastors...say the Devil tempted you, go to some retreat and two moths later come back "cured"...and use it to your advantage