中学AP政治题，美国的任何一州是否可以自己宣布独立？

这其实是个好题目：中学AP 政治题，从法理上说，美国的任何一州是否可以宣布自己独立 without consent from other states?？ Why or why not?

这其实与论坛先前的宪法讨论有关。笔者将贴出一系列的宪法讨论以澄清一些误解。

这问题的一个现实意义是可以比较一下欧盟，欧盟是有退出机制的。呵呵

其实很多美国人提出了同样的问题， Can a state legally secede from the Union? 最高法院大法官安东宁.斯卡利亚给出的回答是 N0.现将他说的理由以英语原文附在这里：

1) the United States would not be party to a lawsuit on the issue
2) the “constitutional” basis of secession had been “resolved by the Civil War,” and
3) there is no right to secede, as the Pledge of Allegiance clearly illustrates through the line “one nation, indivisible.”

其实早在 1869, In Texas v. White, the United States Supreme Court ruled unilateral secession unconstitutional.  最高法院大法官 Salmon P. Chase 就回答了这问题：
“The union between Texas and the other states was as complete, as perpetual, and as indissoluble as the union between the original states. There was no place for reconsideration or revocation, except through revolution or through consent of the States.”