One thing that might be mandated is that federal elections should be conducted in a way that results should be available in a timely manner, with auditable results (ie. a paper trail). If the state wants to run its own, non-federal, elections via mail, or to slow the voting process down with multiple local referendums and state mandated required documentation they may do so... on a separate election date. Their choice, their expense. Federal elections are too important to be left uncertain when any one state can't get its act together. They offer too tight a timeline to permit avoidable delays by one or a few states. Voting just for your one representative every 2 years, president every 4 years and a senator twice in six years can be done as quickly as the election monitors can validate your eligibility. With equally quick provisional ballots for those with questionable validation. At worst, when both senate seats were open, you'd have four boxes to check. If they can't figure out and remember which four before walking in the door I don't want them voting.
There will always be some unusually close races getting contested, but the system's design should provide believable results of election day voting in the vast majority of cases. Military absentee voting needs looser time limits than whatever is allowed for civilian absentee voting. Civilian absentee voting should be sufficiently limited so as to seldom delay final results. The cut offs for each should be designed to permit a timely transfer of power and not be overridden by judicial whim. For their own elections the states may screw thing up without federal interference, so long as the results don't interfere with the federal constitutional responsibility to ensure each state's citizens a republican form of government.
Agreed. How could those people be confirmed to be such? A Doctor's letter? A multi-witnessed and notarized letter to the Secretary of State in each State? Ideas?