What might happen to earth's climates if the earth were not tilted on its axis.

It would either very hot or very cold. No in between.

The side facing the sun would remain around 40-79 deg. Fahrenheit (5-30 deg celsius)

the side facing away from the sun would be dry, moderate or continental

It is the doctrine that the us had the right and duty to expand throughout north america. it just means they believed they had the right to expand westward and they did! they stated with the 13 colonies and then they kept moving gaining different territories throughout the years