Disqualification of a synagogue president

Hi,

One who is known (and not only rumored) to violate Shabbat knowingly is disqualified to serve as a synagogue president. However, if he thinks what he is doing is permitted then he is not disqualified.

(Rav Moshe Feinstein, Igrot Moshe Orach Chaim 3:11)

Have a great day,
Mordechai