Democratic processes may not take the welfare of future generations sufficiently into account and thus may not achieve sustainability. We show that the dual democratic mechanism ? rejection/support rewards (RSRs) for politicians and elections ? can achieve sustainability. RSRs stipulate that incumbents who are not re-elected, but obtain the majority support among young voters receive a particular monetary or non-monetary reward. Such rejection/support rewards induce politicians to undertake long-term beneficial policies, but may invite excessive reward-seeking. We identify optimal RSRs under different informational circumstances.