The Thirteenth Amendment, which amended a part of the original Constitution by banning slavery and indentured servitude, was ratified by the newly reunited states in 1865. I’m just guessing, but I doubt if there was widespread celebrating in the streets. In all probability, many Americans were at best indifferent to the amendment, and many — particularly in the South — certainly opposed it. But it was the right thing to do.
In 1920, the states ratified the Nineteenth Amendment, which said that the right to vote could not be denied because of sex. Once again, this amendment was probably not universally popular. But once again, it was the right thing to do.
Despite what would almost surely be widespread approval, an amendment banning gay marriage would be the wrong thing to do. It would go against the very essence of the Constitutional amendment process. In the first place, amendments are intended to make changes to what the Constitution already defines — and marriage is not something the Constitution gets into. Such an amendment would be blatantly out of place.
In the second place, it would reverse the trend that expands and clarifies rights established by the amendment process. In addition, it would contradict the Fourteenth Amendment, which guarantees equal protection under the law. Since it’s been left up to the states to write laws governing marriage, the Fourteenth Amendment already prohibits those laws from establishing biases of any kind, except where legal age is involved.
Some candidates for Congress still cling to the gay marriage ban as a campaign issue, because it appeals to widespread homophobia. But in this case, as in cases in the past, the majority isn’t right.