1844] Presidential election : triumph of the Democrats. 393 To the surprise of Upshur, the offer of a treaty was at first declined by Texas ; but in January, 1844, the question was asked, whether, if the offer were accepted, the United States would protect Texas against attack before the treaty was ratified ? Upshur made no answer ; but the American agents in Texas, when asked the same question, answered yes ; and the next day an envoy was sent to the United States, with full powers to frame a treaty of annexation. Before his arrival, Upshur was killed by the explosion of a gun on the U.S.S. Princeton ; and John C. Calhoun became Secretary of State. The treaty now went rapidly forward. On April 12, 1844, the instrument was signed ; ten days later it was sent to the Senate ; and the question of annexation was forced into the presidential campaign. Neither of the prospective candidates desired such an issue. Indeed, both Clay and Van Buren, in letters published in the newspapers, declared themselves opposed to annexation at that time, on the ground that its constitutionality was doubtful, and that it was sure to bring on war with Mexico. But the Democratic National Convention which assembled in May rejected Van Buren and nominated James K. Polk, and in its platform declared for the "re-annexation of Texas and the re-occupation of Oregon at the earliest practicable period."" The Whigs nominated Clay, and said nothing about Texas or Oregon. The Liberty party chose for their leader James G. Birney. Scarcely had the news of the nomination of Polk spread over the country when the Senate rejected the treaty (June, 1844), chiefly because many members did not believe that annexation could be accomplished by treaty. Congress, says the Constitution, may admit "new States" into "this union" words that were interpreted to mean that Congress, and not the treaty- making power, viz. the President and the Senate, may admit States. Tyler now appealed to the House of Representatives to take such steps as might be necessary ; but the House did nothing, and the issue was left to be settled by the people. The contest in any event would have been close; but Clay's letter drove great numbers of Whigs into the Liberty party, lost him the electoral votes of New York and Michigan, and gave the election to Polk. This triumph of the Democrats was hailed by Tyler with delight ; and, in his annual message of December, 1844, he asserted that a "controlling majority of the States" had declared for immediate annexation ; that both branches of Congress had been instructed ; and that, in his opinion, measures should be taken to carry out the will of the people. That the Senate would consider itself instructed, and that two-thirds of the members would approve a new treaty of annexation, was far from likely. The House of Representatives therefore passed a joint resolution annexing Texas, with the proviso that in such State or States as should be made from territory north of 36 30' slavery should be prohibited. To this the Senate, after a long debate, added an OH. xn.