First, go read Article I, Sections 1 and 2 of our Texas Constitution of 1874. Flawed as that document is, it does contain those sections, and for that, I'll forgive it all its other shortcomings. (Here, I'll help you. This is from http://tarlton.law.utexas.edu/constitutions/text/IART01.html )
SECTION 1. Texas is a free and independent State, subject only to the Constitution of the United States; and the maintenance of our free institutions and the perpetuity of the Union depend upon the preservation of the right of local self-government unimpaired to all the States.
SEC. 2. All political power is inherent in the people and all free governments are founded on their authority, and instituted for their benefit. The faith of the people of Texas stands pledged to the preservation of a republican form of government, and, subject to this limitation only, they have at all times the inalienable right to alter, reform or abolish their government in such manner as they may think expedient.
Now, think about this: The reconstructionist carpetbaggers had an 'advisory' role in Texas adopting a 'suitable' constitution before readmission as a state would be complete. This means that the feds approved this wording.
The basic premise set forth in the US Declaration of Independence of 1776 is reiterated and validated by the feds when they signaled, by declaring Texas "reconstructed", that these two sections were valid and recognized by Washington: That Texans have the innate right of self-determination.
Incidentally, this is a big part of why a Tenth Amendment resolution never gained traction in Texas. Our ancestors were 130 years ahead of the other states, as our 10th Amendment resolution is the FIRST thing asserted in our state constitution!
More later. Comments welcome. Lively discussion in comment section eagerly solicited. Moderation will be limited to ad-hominem attacks and gross stupidity.