He's a side affect of secularism, yes. In the primaries Drumpf consistently did among his best with Republicans who were not religious. A trend foreshadowed by the heavy public opposition to the Clinton impeachment, amusingly enough.
I'm not sure why so many Democrats are so obsessed with reliving the late 20th century religious debates. Most of those evangelicals are dead now, and the few left have no influence on cultural politics in any way at this point (I would argue they never really did). Talk about a Sore Winner Syndrome.
Hmm.. let's see: the wedding cake controversy, North Carolina's bathroom bill, Kim Davis, all within the past few years. You can still be fired for being gay in a majority of states and there are still other human rights issues out there where it's perfectly okay to discriminate against LGBTQIA people.
I agree that the Religious Right's political clout is (thankfully) significantly waning, but that's all the more reason why people should care and pay attention. Look at what's happening with the Trumpification of the Republican Party. They know that demographics are eventually going to reduce them to third-party status as their base of angry old white heterosexual men slowly but surely die off and that's why they're engaging in voter disenfranchisement and suppression efforts across the country to prevent racial minorities from voting. The Religious Right is no different. They hope that people assume that just because marriage equality is the law of the land that that means that everything is equal for LGBTQIA people in other aspects of their lives in hopes of those supporters becoming complacent. No, the Religious Right is trying to go out with a bang, and we need to STAY WOKE so that we can fight them on every issue to the bitter end when they can no longer impose their discriminatory religious beliefs on everyone else.