Where is your data? According to Allahpundit, Romney got considerably more evangelical support than McCain.
Moreover, I don’t care for the term evangelical because it is a term that has been stripped of all meaning. I am a conservative Southern Baptist, a Calvinist. I am considered an evangelical, but so is Jimmy Carter, another Baptist. Jimmy and I would agree on virtually nothing beyond the time of day. Romney (or Rick Perry/Newt/Santorum) was never going to get the votes of those evangelicals whose understanding of the Bible approximates Jimmy Carter.
From Allahpundit at Hotair.com:
“One question I’m seeing in the comments is, “Did evangelicals turn out for Romney”? Yep, looks that way. Turnout among Protestants generally dropped slightly from 2008 (54% to 53%) but Romney’s share of the vote increased from 54% to 57%. Among white evangelicals specifically, turnout was steady at 26% of the electorate from four years ago and Romney took 78% of the vote compared to just 74% for McCain. If you’d rather slice the data by how often people go to church, the number who attend at least weekly rose from 39% in 2008 to 42% this time. McCain won 55% of that group. Romney won 59%. He improved on McCain’s numbers among Jewish voters too, from 21% of the vote in 2008 to 30% this time (or maybe more), the highest take for a Republican since 1988. If there’s any religious group that underperformed for him, it’s Catholics. He did improve on McCain’s numbers — from 45% to 48% — but O still won a majority despite the abortion-rights jamboree at the convention and the contraception mandate. Catholic turnout was down two points this time, however.”
http://hotair.com/archives/2012/11/07/looking-at-the-national-exit-poll/