They want to control the Republican Party. They want to control government by any means possible; if not through a majority, through obstruction.
They want to control -- and limit -- freedom and civil rights; always have. Before 'the gays' it was controlling and restricting minorities. They want to control what people do in their bedrooms as well. And when they don't get their way, when they don't get the control they want, they make threats. Threats that God will HATE America, threats of earthquakes, threats that global warming related droughts are GOD punishing everyone for not conforming to their religion. "Demons will getcha!" and other rubbish suitable ONLY for scaring foolish or very young children is their fall back position. These are people who fear children will 'catch the Gay' from Common Core, or who will 'catch the Hindu' from gym class, like it was athlete's foot lurking in the showers.
There is no rational limit on the scope of what crazy Evangelicals will try to blame on gays, or for occasional variety in their religious insanity, abortion. Most of these Evangelical extremists are very flexible; they can flip between the two with gymnast-like agility.
It is not rational adult thinking; it is an irrational emotional position, one of ugly emotions, not nice emotions. It is vindictive and revenge driven. Losing the marriage equality battle, and most likely the entire culture war, they seek their last possible way to lash out, to hurt others. These are the people, these mean, mostly old, mostly white Evangelicals FROM WHOM WE NEED PROTECTION to ensure civil rights and true liberty. They are the people who want to create second class citizens, whom they can threaten with losing their employment, losing their housing, or being treated badly when they celebrate a happy life milestone. People should be free to believe whatever they like, reasonable or crazy, personally and privately; but it is also appropriate to draw the line at intruding the discriminatory or the freakishly weird into the public square and then imposing it on everyone else. This is NOT an attack on religion nor is it a criticism leveled at all religion; freedom of religion is freedom to believe whatever you like, but it is not freedom from criticism or freedom from reason.
One of the most apt statements I've seen so far is that Evangelicals desperately want religious freedom, they want YOU to be FREE TO FOLLOW THEIR RELIGION, not your religion (or absence of religion) of choice and conscience.
The most extreme of these people want to declare open hunting season on anyone they perceive to be LGBT, with it being legal to murder them at will. That was the legislation proposed in California by a particularly hateful bigoted Evangelical. Because...Jesus?
I could re-type in all the numbers, the breakdowns, but this analysis by both party affiliation, age, and religious affiliation does a much better, more dynamic job of it, and shows why this will be important in the 2016 election:
Individually, most of these Evangelicals are nice people, but their religion and their politics are ugly and hateful, and as a political movement, they should be repudiated and rejected. They use the word freedom, often; but they seek to stifle it and to control people, to coerce people to conform to their beliefs. They wail and rant against big government overreach and intrusion, but they seek to expand it. They smear lipstick on their pig,, discrimination, by calling it religion and freedom.