How did the assembly's reforms decrease the power of the first and second
estates?

Each Estate had one vote. The national assembly met together in a tennis court and refused to leave until they instituted a new constitution. ... Because they thought that all men were born and created equal and it wasn't fair that the first and second estate had more rights and power than them and they wanted equality.

the federalist party which advocated strong centralization dominated the united states government till 1800. so 1800 election transformed the power from one party to another party for the first time and was thus a turning point in american history. so jefferson called it "revolution of 1800".

explanation:

(1)representation based on state population (2)all states have equal representation apex