You can't force acceptance. You can get every state in the nation sanctioning "gay marriage", but you can't force the populace to accept it, especially if it violates their core belief system or right and wrong.
What is love to some is sodomy to others. That does not mean those of us who do not agree with the "gay marriage" advocates here hate our brothers and sisters of the human race. We just disagree what marriage is. Marriage is a heterosexual union for the procreation of families through a contractural relationships.
1 billion homosexuals marching and chanting can't change this truth. I am sorry but this is the way it is. A dog is a dog, a tiger a tiger, a man is a man, and woman woman. Marriage is between a man and woman in most societies. In polygamous it is between one man and several women or one woman and several man(I have seen National Geographic), but never homosexual in nature. Even isolated tribes in the world who live life circa 5,000 years ago practice heterosexual marriage.
Now marches and protests have two outcomes. They either work for you or against your cause. It depends on the subject being protested AND how those who protest act. Most protesters are peaceful, but some on the lunatic fringe have been harrassing, vandalizing, intimidating, and persecuting. Not a great way to get what you want.