Answer:
1. The central idea of the text is to present the reasons why the USA should prepare itself to face the Mexican army.
2. According to the text, the USA had a reason to go to war against Mexico.
Step-by-step explanation:
The central idea of a text is the main subject that the text presents. In the case of the text shown above, we can see that this main issue is the need for the United States to prepare itself to face Mexico in a war. This can be seen from the fact that the author of the text says that Mexico is unfairly threatening Texans and that it is the duty of the USA to help Texans defend themselves against such an aggressive invasion. This can be seen in the lines "The invasion was threatened solely because Texas had determined to annex berset to our Union; and under these curcumstances, it was plainly our duty to extend our protection over her citizens and soil The Congress of Texas"
The text also shows that the USA has a reason to enter a war against Mexico, because Mexicans dared to cross the border, enter the USA illegally and kill American citizens.