That's what I thought as well, until a freeper from the Oneness Pentecostals came up and said she was an evangelical and they didn't believe in the Trinity as she said it was unbiblical.
So one can't even use that -- the entire "evangelical" bogeyman in the MSM doesn't make sense
As with all labels of differentiation, evangelical (as re. the modern movement) became broader as time went on, and originally is was synonymous with fundamentalist. For is began as a result of regenerated believers who highly esteemed Scripture as their sure supreme standard, and we unified in and committed to core thus fundamentals. And arose (early 20th c.) in reaction liberal theological revisionism. And likewise they arose as a political force in the 70's, and tend to vote around 80% for the conservative poetical candidate for President.
But pollsters tend to class respondents as evangelical if they affirm they had some sort of born again experience by which one entered into a “personal relationship” with Jesus Christ.