What are the advantages of Ballot Propositions in the USA?

Direct DemocracyUpholds government of the people, for the people, by the people, allowing strong political participation and high popular sovereignty. Shows influence of society upon pressing political issues.(e.g. California legalized recreational marijuana - one of the largest recreational marijuana markets globally, projected to reach $22bn by 2020 - impacting local economy, society should be able to impact the decisions made on this)

Increased TurnoutIf the ballot includes issue that affect voters then they are more likely to vote, therefore increasing the turnout within elections. This makes it a more proportional and pluralist vote rather than the sovereignty residing in the hands of a small, minority, elitist group giving a more powerful decision with weight behind it.(e.g. On average, turnout in presidential elections increases by 0.70% with each initiative on the ballot, whereas turnout in midterm elections increases by 1.7%, all else equal)
Reflects Societal IntentionsEnhances pluralism amongst the political system. Allows society to decide on controversial issues that many senators wouldn’t want to associate themselves with. The issues are pressing against society and allow a government for the people, by the people, for the people to be established. (e.g. 2006: Michigan passed a proposal 58%-42% restricting affirmative action to stop race becoming a qualifying factor when applying for schools and jobs - shows growing influence of the Modern Civil Rights Movement, pressing for further equality)
Increased ParticipationThe process of ballot propositions and initiatives helps increase political participation therefore enhancing the Democratic process of the US. It limits the power of strong central and federal government by putting the power in the hands of the electorate, therefore acting as a check and balance upon both the Executive and the Legislative.(e.g. 2016 Maine, marijuana legalized for personal use, 50.2%-49.8% passed)