The Constitution is very specific that it is up to each State to make rules to govern how their Electoral College electors are to be chosen. It wasn’t until 1836, I believe, that all States finally held elections to determine the electors. In 1832, South Carolina, for example, had their electors chosen by the State Legislature.
Maine and Nebraska already divide their electors this way, so there is certainly current precedent.
This plan is a good one for us.
Pennsylvania is clearly a state where this system would benefit us.
New York, California, it would benefit us.
Texas, it would not benefit us.