This is, and always will be a ridiculous idea.
The elctorial system simply reflects the desire of the majority of congressional districts within a state, then of states within the country. It prevents mob rule. Of course, not all electors get thier way. If three districts out of twenty in one state voted for greens, and the rest for blues..the state goes to the blue. It is, after all, a republic, not a straight democracy.
It's the same reason that the number three guy in succesion to the president is the speaker of the house. He is closer to the people, by choice, than any individual in congress. He is chosen by majority election within the house. A house that clearly represents each district of the US.
Not necessarily. If a state wants to give 15% of the electoral votes to green and 85% to blue, it can do that. Maine and (I think) Nebraska both allocate electoral votes on a district by district basis. Winner-take-all is not Constitutionally required. The Constitution only says,
Each State shall appoint, in such Manner as the Legislature thereof may direct, a Number of Electors, equal to the whole Number of Senators and Representatives to which the State may be entitled in the Congress.