Because they had more support from the beginning. And they had slaves which supported the factories in the North. The North relied heavily on them.
The passage shows that Californian politics, and in particular, political advancement methods, were not wholly bound by law as they are now.
Governmental institutions and government control was weaker at that time, so it was difficult to enforce the law consistently. Because of it, people did not have a strong commitment to following legal paths for advancement. Revolutions and rebellions were more effective in seizing power than political campaigns, and there were few negative repercussions for those who chose that method.
He is basically saying that in a country few should rule (oligarchy). These would be the wisest and the best. These rulers are elected. To keep this system efficient he suggests that these rulers should only stay in office for a short period of time, so that the people keep deciding how their country should be
The 10th Amendment is used every time the state or local government passes a law. It's what gives (in theory) the states broader power than the federal government.
It's also why the state can refuse to enforce federal laws and so the federal government often "encourages" certain laws/policies by threatening to withhold federal funding.
1) Vietnam war was officially ended whereas Korean War ended in a Cease-Fire which means it never ended in official way
2) Korea was a short war and Vietnam was a Long war
3) Korea was like WW2 Whereas Vietnam was similar to Guerilla War
Hope this helps!