A somewhat radical political proposal...

One problem we have in the US is that "off-year" (2010, 2014, 2018) election years generally have very low turnouts.  This is a problem, because it leads to very low turnouts for half of the elections of senators and congressional representatives, and for many state and local offices.  This is exacerbated by localities that have off-off year elections, as Indianapolis does--it elects its mayor and city council and other local officials the year before presidential elections--2011, 2015...(in Marion county 22.7% of registered voters voted in 2015, compared with 56% in 2012--which is itself shamefully low).

So what I propose is making all elected offices be for a term of 4 0r 8 years, and holding all elections in the same year as the presidential election.  (This will require a constitutional amendment, altering terms for representatives to 4 years, and senators to 8 years.)