I did read it, did you? Or were there too many big words in this part?
"Considered therefore as transactions under the Constitution, the ordinance of secession, adopted by the convention and ratified by a majority of the citizens of Texas, and all the acts of her legislature intended to give effect to that ordinance, were absolutely null. They were utterly without operation in law. The obligations of the State, as a member of the Union, and of every citizen of the State, as a citizen of the United States, remained perfect and unimpaired. It certainly follows that the State did not cease to be a State, nor her citizens to be citizens of the Union."
Chase's problem is that there is NO prohibition against secession. Texas had a republican government. That government (and others) called for elections to conventions. Those conventions met and resumed the powers they had delegated. The 1845 Texas Constitution, recognized as republican stated:
We, the people of the republic of Texas, acknowledging with gratitude the grace and beneficence of God, in permitting us to make a choice of our form of government, do, in accordance with the provisions of the joint resolution for annexing Texas to the United States, approved March first, one thousand eight hundred and forty-five, ordain and establish this constitution.That the general, great, and essential principles of liberty and free government may be recognised and established, we declare that
SEC. 1. All political power is inherent in the people, and all free governments are founded on their authority, and instituted for their benefit; and they have at all times the unalienable right to alter, reform, or abolish their form of government, in such manner as they may think expedient.