Evangelical Protestants do have great diversity in their membership, but as a whole, they skew far to the right compared to mainline Protestants. Mainline Protestants support same-sex marriage, 57-35, while Evangelicals oppose it, 64-28. Similarly, mainline Protestants believe homosexuality should be accepted, 66-26, while Evangelicals believe it should be discouraged, 55-36.
The "bible thumpers" you are talking to are more numerous than you realize. And they do have a lot of power over the GOP, as they are more likely to identify as "conservative" (55%) and "Republican" (56%) than any other religious group save Mormons.
Source: Pew Religious Landscape Study, which is probably the same study Rock cited, and is the go-to study for understanding the state of religion in America.
https://www.pewforum.org/religious-landscape-study/
Yes, this is much closer to the definition that I have carried forever. But different than the definitions I read with Webster and similar sources.
I know a lot of Protestant believers but very few that meet what I always considered evangelical.