Question Can the bride make it mandatory on the invitation for all male guests to wear a tuxedo?

Answer
What wedding guests choose to wear is ultimately up to the individual guest. Certainly, the bride and groom can decide on a very formal wedding reception (ie. black tie) and while that will strongly encourage male guests to wear dark suits/tuxedos, there is still no guarantee that every single male wedding guest will show up at the reception wearing a tuxedo. This right belongs to each individual male guest.