What was a major reason president lyndon b johnson decided to not run for reelection in 1968?

Between the world wars eisenhower's presidency the 1960s what is the organizing principle of this list?

Which of the following best describes the 1957 events at central high school in little rock, arkansas? -governor faubus resisted the school’s integration with national guard troops, and president eisenhower sent federal troops to enforce integration.-under governor faubus, little rock police first fought, then enforced, the order to integrate the school.-president eisenhower sent national guard troops to resist the school’s integration, but governor faubus obtained a court order to dismiss them.-president eisenhower and governor faubus worked together to make the integration process run as smoothly as possible.

After ww2, the soviets began setting up what type of governments in countries closest to them