"If the people will let us alone," he cried, "we will preach the gospel in peace. But if they come on us to molest us, we will establish our religion by the sword. We will trample down our enemies and make it one gore of blood from the Rocky Mountains to the Atlantic Ocean. I will be to this generation a second Mohammed, whose motto in treating for peace was 'the Alcoran or the Sword.' So shall it eventually be with us - ' Joseph Smith or the Sword.'"
It's curious that never came up during the Romney campaign.
[In the second paperback edition, revised and enlarged, 1995, pp. 230-1.]