How many people in the blue states agree gay marriage?

MY question refers to U.S.A:I was loking at some statitic and I saw that only 55 per cent of people in NYC agree gay marriage,and it s kinda hard for me to belive that the support itțs so low,considering we are talking about a comopolitan city.I am not sure how true are the statistic mde in USA and I know know exacly the way of doing them.The statistic I am talking about supposed to be made on voters.