Wikipedia comes through with a list of vice presidential nominees who have favored the dissolution of the United States. We've got John Tyler, Whig, 1840; William Graham, Whig, 1852; John Breckinridge, Democrat, 1856; Herschel Johnson, Democrat, 1860; Sarah Palin, Republican, 2008. As you can see, there are more Democrats -- and Whigs -- than Republicans on this list, so Palin is in the clear. Of these, John Tyler actually became president, but he didn't dissolve the country. In fact, he actually supported annexing Texas and making it part of the union.
