What were the reasons for the political status of Texas becoming such

What were the reasons for the political status of Texas becoming such a divisive domestic political issue in the United States in the early 1840s?

Which political, economic, or moral reasons were most important in moving the United States towards war with Mexico?

ANSWER
Answer: An ideal answer will:
1. Discuss and define what Manifest Destiny meant to the American colonists and settlers who immigrated to Texas and American political supporters of the concept, focusing on the economic, patriotic, and Protestant Christianity elements of Manifest Destiny from the 1820s-1840s.
2. Discuss and define how the overwhelming presence of American settlers in Texas, accompanied by many slaves, by 1830 spurred the Mexican Congress to close Texas to further American immigration and the importation of slaves.
3. Discuss how the armed revolts of American colonists in Texas during the 1830s provoked the Mexican government into engaging in an all-out war with the Texas colonists that ultimately resulted in a successful war of independence, attracting the political attention of advocates of Manifest Destiny in Washington, D.C. Emphasize how the establishment of an independent Republic of Texas and the expressed desire of its leaders and constituents for annexation by the United States placed the issue front and center on the national political agenda by 1836.
4. Discuss how the prospect of Texas becoming a huge slave state caused many politicians from the North and Midwest, and even President Andrew Jackson, to oppose annexing Texas in the 1830s because of its destabilizing political effects on the nation.
5. Discuss how Northern abolitionists, opponents of expanding slavery to new territories, and opponents of Manifest Destiny, in general, increasingly viewed the issue of annexing Texas in moral terms, emphasizing their opposition to the expansion of slavery and the fears of provoking a protracted and deadly war with Mexico over this morally dubious venture.
6. Discuss how the provocative political, diplomatic, and military actions of Presidents Tyler and Polk in the early-mid-1840s to manage the U.S. annexation of Texas aroused the ire of Congressional opponents of war with Mexico, such as John Quincy Adams and Abraham Lincoln, who asserted that Polk, in particular, deliberately undermined a possible diplomatic settlement and territorial compromise with Mexico over Texas that would have avoided war.
7. Write a concise and effective conclusion.