The most vociferous opponents being actually in the closet themselves is a pretty well known phenomenon.
As the phrase goes (Albeit a bastardised version from the original), 'Methinks the lady doth protest too much'.

It surprises literally no-one when someone who spent their political career bashing homosexuals turns out to be gay themselves, but there is a fine line to be noted. Loathing/Fear born of ignorance can look very similar to that born of self loathing, so I wouldn't go as far as to say that anyone who is homophobic is actually gay but the odds certainly run in favour of that.