Because each state has independent power to award its electoral votes in the manner it sees fit, it is difficult to see what "adverse effect" might be claimed by one state from the decision of another state to award its electoral votes in a particular way. It is especially unclear what adverse "political" effect might be claimed, given that the National Popular Vote compact would treat votes cast in all 50 states and the District of Columbia equally. A vote cast in a compacting state is, in every way, equal to a vote cast in a non-compacting state. The National Popular Vote compact does not confer any advantage on states belonging to the compact as compared to non-compacting states. A vote cast in a compacting state would be, in every way, equal to a vote cast in a non-compacting state. The National Popular Vote compact certainly would not reduce the voice of voters in non-compacting states relative to the voice of voters in member states.
The electoral votes of the non-compacting states would continue to be cast in the manner specified by the laws of those states. The electoral votes of the non-compacting states would continue to be counted in the Electoral College in the manner provided by the Constitution. In practical terms, that means that the non-compacting states would continue to cast their votes for the winner of the statewide popular vote (or district-wide popular vote in Maine and Nebraska) after the National Popular Vote compact is implemented. No non-compacting state would be compelled to cast its electoral votes for the winner of the national popular vote.
The electoral votes of the non-compacting states would continue to be cast in the manner specified by the laws of those states. The electoral votes of the non-compacting states would continue to be counted in the Electoral College in the manner provided by the Constitution. In practical terms, that means that the non-compacting states would continue to cast their votes for the winner of the statewide popular vote (or district-wide popular vote in Maine and Nebraska) after the National Popular Vote compact is implemented. No non-compacting state would be compelled to cast its electoral votes for the winner of the national popular vote.