I mean sure and I believe states do have a right to choose their own electors. However, the issue is running an election and then aggregating the results with the other states. An election is a legal event and the constitution requires the states to conduct elections in a representative format, which is violated if they then defer to the electoral results of another state. On the other hand if the representatives of that state decide who the electors will vote for, that is still a representative form of government in which only the citizens of that state are represented.