Some enterprising YouTuber has corrected an old error, and uploaded a 2002 of Mitt Romney speaking from French in fully embeddable form. (An old version of the video was unembeddable, denying it to so many people.)
In 2007, Gingrich cut a Spanish-language apology for comments in which he called Spanish the "language of the ghetto." The video has been removed from YouTube; its last remnant is as part of one of the way-too-plentiful Young Turks commentaries on politics.
The only candidate who doesn't keep this sort of content in the vault where George Lucas keeps the "Star Wars Christmas Special" is Jon Huntsman.