Politicians choose mixed selection generally because such systems allow government and sometimes other institutions to have a voice on constitutional courts and to diversify the deliberative process. An extensive review of legislative histories reveals that policymakers in both Chile and Colombia chose mixed selection methods for their constitutional courts to create a balance or equilibrium of voices representing different political branches on the courts themselves. To more fully understand how the debates about selection are reflected in judicial behavior, this chapter focuses on how mixed selection methods operate in practice to influence judges’ decisions to veto or strike down laws as unconstitutional.