This “safety valve” theory “appealed to the racial fears of whites in the North,” who feared the prospect of accepting emancipated slaves into their communities if the institution of slavery in the South collapsed.  This plan of racial cleansing was pragmatically consistent with the proposals for the colonization of blacks abroad pursued by a number of American presidents, from Jefferson to Lincoln.  Walker reinforced his position by implying national security concerns and warning that in the event of a failed annexation, Britain would maneuver the Republic of Texas to emancipate its slaves, predicting dangerous destabilizing influence on the slave states of the southwest. The pamphlet characterized the abolitionists as traitors who had conspired with the British to overthrow the United States.   Senate and House lawmakers who were in favor of Benton`s renegotiated version of the Texas annexation bill had been assured that President Tyler would sign the joint House action but leave its implementation to the new Polk administration.  But during his last full day in office, President Tyler, at the urging of his Secretary of State Calhoun, decided to act decisively to improve the chances of Texas` immediate annexation. On 3 March 1845, with the vote of his cabinet, he sent an offer of annexation to the Republic of Texas by mail, exclusively under the terms of the Brown-Foster option of joint housekeeping.  Minister Calhoun informed President-elect Polk of the action, who resigned without comment.   Tyler justified his preemptive decision by saying that Polk would likely be pressured to abandon the immediate annexation and resume negotiations as part of the Benton alternative.  During debates in the House of Representatives, constitutional objections were raised as to whether both houses of Congress could constitutionally authorize the admission of territories, not states.
If the Republic of Texas, a separate nation, were admitted as a state, its territorial boundaries, property relationships (including slave ownership), debts, and public lands would require a treaty ratified by the Senate.  Democrats were particularly concerned about weighing $10 million in Texas debt in the United States, angered by the flood of speculators who had bought Texas bonds at low prices and were now pressuring Congress for the Texas House bill.  House Democrats handed the bill to the Southern Whigs at an impasse.  A variant of Tyler`s “diffusion theory” that played with economic anxiety at a time when slave-based staple food markets had not yet recovered from the panic of 1837. Walker`s Texas “escape route” promised to increase the demand for slaves in the fertile cotton-growing areas of Texas as well as the monetary value of slaves. Owners of silver-poor plantations in the former south east were promised a market for surplus slaves for profit.  The annexation of Texas, Walker wrote, would eliminate all these dangers and “strengthen the entire Union.”  With the ratification of the Webster-Ashburton Treaty in 1843, Tyler was prepared to make the annexation of Texas his “top priority.”  Representative Thomas W. . . .