In this article I examine controversies over the use of referenda and plebiscites for constitutional reform. My chief example is a recent development toward plebiscitary democracy in Australia. Although there is no legal requirement in Australia for a popular vote to legalize same-sex marriage, the federal government considered holding such a vote. Marriage rights provide a key example in which the normative case for direct democratic constitutional reform remains unsettled, and indeed controversial. I rely on deliberative democratic theory to conclude that referenda and plebiscites generally should be part of constitutional reform processes. I nuance this conclusion by outlining categories of legal norms raising distinctive considerations as to whether and when public voting should precede constitutional reform.