What early 20th-century Progressive electoral innovation is still in place today?

Question

Quizplus · Accepted Answer

Nonpartisan elections at the local level were a key Progressive electoral innovation in the early 20th century, intended to reduce the influence of political parties and party machines on the local electoral process. Today, many cities and towns still hold nonpartisan local elections, in which candidates are not identified by party affiliation and party endorsements are not allowed. This allows voters to focus more on individual candidates' qualifications and platforms rather than political parties.

What Early 20th-Century Progressive Electoral Innovation Is Still in Place