Jimmy Carter never won the majority of the Protestant vote running for president.
The only democrat presidential candidates to win the majority of the Protestant vote, were FDR by narrow margins in 1932 and 1936, and LBJ in 1964.
Nope, all those Southern Baptists, Independent Baptists, Evangelicals, Methodists, and a horde of other groups who claim to be Protestant are really not Protestants. They're, well, not-Protestants, right?
LOL, every Baptist preacher within fifty miles of where I live now was in Jimmy's corner and expecting great things from their "born again" bud who now even has his own Bible for sale in Protestant book stores.
One thing for sure, those folks who think no one is Protestant unless they're part of their 12 person clique are a barrel of laughs.