Your statistics are out of date. The number was closer too 70% in 2014, and has been steadily falling since the nineties. From Pew at
http://www.pewforum.org/2015/05/12/americas-changing-religious-landscape/
"the percentage of adults (ages 18 and older) who describe themselves as Christians has dropped by nearly eight percentage points in just seven years, from 78.4% in an equally massive Pew Research survey in 2007 to 70.6% in 2014. Over the same period, the percentage of Americans who are religiously unaffiliated - describing themselves as atheist, agnostic or "nothing in particular" - has jumped more than six points, from 16.1% to 22.8%."
The rate of decline seems to be accelerating. There was only a 10% decline between 1990 and 2008, 18 years (
source ). This was an almost 8% decline in 7 years. Christians will be a minority in America in about 20 years or less at this rate.
There is no murder involved because murder is deliberate, unlawful homicide. Abortion is legal.
Feel free to test that and discover what your rights really are. There seems to be a notion among the faithful in America now that religious sensibilities trump everything else. Many of the rest of us don't agree. If the Supreme Court finds agrees with you and finds in favor of the Masterpiece baker, Americans will be free to discriminate against one another however they choose by claiming religious belief. You might walk into a restaurant with a crucifix around your neck and denied service for that if it offends the religious sensibilities of the restauranteur.
Yes, one should be aware of these people. They also go by the name Reconstructionists. What they are are Christian theocrats, and they most assuredly would bring inquisitions back if given the power:
Are they a real threat? I can't judge that. While the numbers that self-identify as Christian is declining as indicated above, they've already begun creeping into government in much larger numbers. Much of Trumps cabinet are very religious Christians (Betsy DeVos, Rick Perry, Ben Carson, Scott Pruitt), and they're doing exactly what you would expect them to be doing. DeVos (education) is weakening safeguards for LGBT students and reassigning public school dollars to voucher programs - code for religious schools, which is still a long ways from the following:
"Why stoning? There are many reasons. First, the implements of execution are available to everyone at virtually no cost...executions are community projects - not with spectators who watch a professional executioner do `his' duty, but rather with actual participants...That modern Christians never consider the possibility of the reintroduction of stoning for capital crimes indicates how thoroughly humanistic concepts of punishment have influenced the thinking of Christians." - Christian Dominionist Gary North bemoaning the influence that humanism has had
This is the face of Christianity absent the tempering of secular humanism. This is what Islam looks like in the Middle East, which was deprived of the principles of humanism, which enshrined humanist principles in the colonies in the form of a new nation with a secular government and put an end to killing witches.
I've long said that I see no reason to believe that if it had been the other way around - Muslims tempered by a few centuries of humanist influence and Christians still living in theocratic or quasi-theocratic nations - that it would be the Christians throwing homosexuals off of towers and burning infidels alive in cages. Why should we think otherwise? The two religions aren't that different on paper. The differences are the cultures in which they are rendered. Didn't the Dominionist quoted above say essentially that - "how thoroughly humanistic concepts of punishment have influenced the thinking of Christians"? He wants to return to stoning.