"If ‘evangelical morality’ harms others and can’t justify itself, is it ‘unfair’ to mention that..."
"...it's losing the argument?"
Evangelical morality is not losing the argument because it is insufficiently progressive. Evangelical morality is losing the argument because it is insufficiently moral.
Evangelical morality has, rather, demonstrated itself to be immoral to be a source of harm to real people. Those people rightly, justly, and understandably are demanding that this harm stop. Evangelical morality insists that this harm continue, but has thus far been unable to offer any reason why it should. Defenders of evangelical morality are free to keep trying to come up with some plausible justification for such harm being done to others, but they are not free to mandate that everyone else ignore the failure of their attempts to do so thus far.
Because of those two things the real harm being done to real people and the utter failure to provide any credible basis for inflicting such harm this evangelical morality is, in fact, increasingly being shamed out of the public square. This is not happening because the public square is dominated by progressive chauvinists. This is happening because such immoral evangelical morality is, in fact, shameful.
http://www.patheos.com/blogs/slacktivist/2014/07/14/if-evangelical-morality-harms-others-and-cant-justify-itself-is-it-unfair-to-mention-that-its-losing-the-argument/