Recent experiments have shown that a voltage can induce a large deformation in an elastomer of interpenetrating networks. To understand the observation, this paper describes a model of interpenetrating networks of long and short chains. As the voltage ramps up, the elastomer may undergo snap-through instability. The network with long chains fills the space and keeps elastomer complaint at small to modest deformation. The network with short chains acts as a safety net that restrains the elastomer from thinning excessively.