The Wilmot Proviso on the Moon

But to the South it [the Wilmot Proviso] is a practical question - a question of vital, momentous import. It asserts the constitutional right of Congress to entertain legislative jurisdiction over the subject of slavery. What is done here to-day will be plead as a precedent to-morrow. We war against the principle; and if you were to propose to prohibit slavery in the moon, I would stand here and battle against it, as long as I could raise my voice or move a muscle. You have no right to touch the subject; and it is insulting and humiliating to the South, merely because you have the numerical power, to attempt to prohibit slavery, where you yourselves say, it can never go. Let those who move it bear the odium of the consequences.

Georgia Senator Herschel V. Johnson, July 7, 1848.