This early, I see, the demand for "re-annexation" goes hand in hand with the assurance that rather than enlarging slave territory the acquisition of Texas will "prevent the increase of slaves." This is Senator Walker's point early in 1844, and Gansevoort Melville's in his Newark NJ speech just before the election of 1844, although we do not have the words in which Gansevoort developed the argument.
In this, Henry Clay was a Whig and Preston had gone from Nullifier to Whig. Aware that he was making Clay squirm, Preston announced that Clay had been on the right side before he was on the wrong side and now should stand again "on the same ground" that "he occupied from 1819 to 1829."
Walker's "Letter" is also available online. What a toybox the Internet has become!