My husband is on the Board of Directors for a Chamber of Commerce in Okla. He was told he had to resign because I have been charged with a felony. What legal justification would they have for this?

He is in a position of trust, therefore, he can't be married to a felon. Plain and simple.

He does not have to resign of course, he can allow them to fire him

... What legal justification would they have for this?

You could review the by-laws of the COC &/or the Oklahoma Corporate Code (http://www.oscn.net/applications/oscn/Index.asp?ftdb=STOKST18&level=1), to see, but I suspect that the BOD can get rid of one of id's members for any or no reason. It's basically a public relations issue.