Just so. I read and watched with interest the various state attempts to bar Trump as a candidate as it unfolded and sympathized with it. But (you knew that word would pop up) I certainly understand the reasoning of eligibility of federal offices to not be decided by states alone.
Except that's exactly how it was designed. The electors, and the senators and the representatives... they are agents from the state to the federation. This isn't a sovereign nation, but a federation of sovereign states (that's why the president is decided by the electoral college, not the voters).
Why wouldn't a state be able to exercise control over their electors the same as they do over their senators?
Indeed: for a very long time, the states got to chose all the rules of their election. Whether women could vote. What the voting age was and so on.
Note as well: the rules to get on the ballot in each state are *already* different. Every election will have candidates in some states but not others. I haven't seen any movement to throw those laws out or overrule the state in that regard.
If we want to have a national election: Great. I'm all for it. Every vote counts and the person with the most votes wins. But as long as we are having state elections (which is what's happening, we are electing reps for the electoral college), it *should* be up to the state (at least within the limitations imposed by the constitution).