Marriage rights activists will deliver a petition asking Mayor Kevin Johnson to join other mayors in support of same-sex marriage Tuesday morning at City Hall in a move they said they hope will cause him to consider endorsing Mayors for the Freedom to Marry. “We’re not trying to force anybody’s hand or be aggressive in any way,” said Neil Pople, communications director for the Stonewall Democratic Club of Greater Sacramento and author of the petition. It has more than 300 signatures and is posted here. “We want to positively encourage the mayor and let him know that there are people who want this to happen.” Last week’s ruling by the Ninth Circuit Court of Appeals against Proposition 8 –