Why did Hosni Mubarak's rule in Egypt last thirty years, and why did it fall in a mere eighteen days? This dissertation uses Mubarak's Egypt as a case study for understanding how autocratic regimes can use formally democratic institutions, such as multiparty elections, to "trap" their opponents and thereby enhance their durability, and also investigates the extent to which this strategy may undermine regime durability. Through over 200 interviews conducted in the months preceding and following the 2011 Egyptian uprising, I find that autocratic regimes can manipulate legal opposition parties to coopt their opponents and thereby prevent them from revolting. But over time, the strict limits under which regimes permit their "trapped" parties to operate undermine these parties' credibility as regime opponents, and thus encourages newly emerging oppositionists to seek other - potentially more threatening - means of challenging their regimes. As a result, regimes that rely on "electoral authoritarian" institutions to enhance their longevity may be more vulnerable than the literature commonly suggests.