1968: Bobby Kennedy alive

[ATFFL]

By 1980 the US would be all red, as in Communist.  He would have pulled out of Vietnam and gutted US military spending and turn it into handouts to the poor.  By 1976 the US military would be a paper tiger.  When faced with a Soviet invasion of Europe in 1978, he would choose to surrender instead of launch a world ending nuclear war.

In 1984 the Soviets would invade China, which would respond with nuclear weapons.  The USSR and China would be devastated in the war; neither could be considered a nation state.

This would shortly be followed by a general insurrection in the US, which has seen a large amount of partisan style resistance thanks to the right to bear arms, which was suspended shortly after the surrender.  Without a mother country, the occupying Soviet soldiers would be heavily outnumbered and without a lot of armor/air support, which was shipped home before being lost in the Sino-Soviet War.  They would surrender and Premier Kennedy, allowed to keep his positioning the surrender, would be overthrown and democracy restored. 

Laissez-faire economics would be the word of the day, with an income tax used primarily to support a large and capable military.  The new Constitution would clearly limit the powers of the government with an exact and exhausting list of powers they can exercise.   Today's Republican Party would represent the political left of the political spectrum in the United States.

Without as many weapons available to the population, Europe would take longer to get out from under the grip of communism.  After they do, fascism would rise again for a while, before it too falls and a European Union is established with a general weakening of national power.

Asia, having seen a nuclear war, would be royally screwed.

Africa would still be a screwed up mess.

Israel would actually be a bit better off.  Without the US supporting it, the Soviets would not back the Arab states against it.  Why arm your next conquest?  Iraq never gets nuclear technology from the French. 

South America is in better shape thanks to US refugees bringing money and knowledge.