A useful way to hold this phrase: picture a group standing up in public and saying two things at once — we know what is right, and there are more of us than of you. The second claim is what gives the first one its force. Nobody has counted, and that is exactly the point: the numbers are asserted, not measured. Every use of the phrase, from the organisation that took it as a name to the cool way a newspaper uses it today, is standing on that double claim.
The name was coined by the conservative activist Paul Weyrich in 1979, and became widely known through the televangelist Jerry Falwell. So the phrase started as a claim made on purpose, and the lower-case general use kept both halves of it: the moral standing, and the assertion of numbers.
根據資料，這個名字是一九七九年由保守派人士 Paul Weyrich 造出來的，後來透過電視佈道家 Jerry Falwell 廣為人知。也就是說，這個說法一開始就是刻意提出的主張。後來小寫的一般用法把兩半都留了下來：道德上的位置，加上人數上的宣稱。
Wiktionary entry for 'Moral Majority' (etymology text supplied in this evidence packet): 'Coined by conservative activist Paul Weyrich in 1979 and later popularized by televangelist Jerry Falwell.'
Two branches
一般說法：以道德自居的那群人
這一支就是核心畫面本身，只是脫離了美國政治的脈絡，可以用在任何社會上。
noun · C1
The moral majority means the people in a society who hold strong, traditional beliefs about right and wrong behaviour, and who are sure that their own beliefs are the correct ones for everyone else too.
道德多數（自認代表主流道德的人）
美國政治：專名，以及以專名泛稱的一群人
這一支不是比喻，而是有人真的把核心畫面裡那兩句宣稱，拿去當成組織的名字，然後名字又反過來變成一種泛稱。
noun · C2
The Moral Majority was an American Christian political organisation, started in 1979 by the Reverend Jerry Falwell. It supported politicians who shared its right-wing views on questions such as abortion and the rights of gay people, and worked against politicians who did not.
道德多數派（美國宗教政治組織）