I worry about this, and about a great many things regarding politics.
The main danger (if this assertion is correct) is a lower african-american turnout. That would be something between 'a shame' to a 'disaster'. If a preacher can cool a congregant enough so they are conflicted, they might choose to just sit it out. I hope they don't.
The idea that blacks are to any degree, homophobic, if true, is a problem, but it's not one we (those who support the president and hope for equality for gays) can immediately do anything about. I'm sure most people who are for 'traditional values' are the product of their generation and those which preceded it. It will take time for minds to change. In the meantime, we need to do everything we can to nudge society in the direction of progress. The president has done a good job. We do it here, and I hope, carry that on to the people in our private lives.