The U.S. citizenship and voting age requirements could be modified for state or local elections. They may not be changed for federal elections as they are part of the 26th Amendment.

The U.S. citizenship and voting age requirements could be modified for state or local elections. They may not be changed for federal elections as they are part of the 26th Amendment.
For example, San Francisco voters previously voted on the issue of whether to allow non-citizens to vote in school board elections.
Another example is the issue of whether to allow U.S. citizens under the age of 18 to vote. This was the subject of Proposition F in the last November election for San Francisco voters. The possibility has been previously discussed in California State Legislature committees to allow U.S. citizens under 18 years old to vote. There has been debate about what age to allow voting (14, 16, 17) and whether it should be a fraction of a vote (1/4 or 1/2) until the age of 18.
You can view these propositions in the link included from the 2016 San Francisco election of San Francisco materials -please see Propostion F and Proposition N.
Do you believe there should be modified standards for state and/or local elections. If yes, explain your answer and be specific about what changes and why. If no, explain your answer and explain why not.