I present a search for the associated production of the supersymmetric particles, the chargino and the neutralino carried out with 2.0 inverse femtobarns of integrated luminosity collected by the CDF experiment at the Tevatron ppbar collider. The signature is the three lepton and missing energy "trilepton" signature. For a specific choice of parameters of the mSUGRA model, 11 supersymmetric events are expected, but the observation of 7 events is consistent with the standard model expectation of 6.4 events. The mSUGRA model of supersymmetry is constrained and charginos with masses up to 145 GeV/c2 are ruled out. I also discuss a method to apply the observations to generic susy models with a similar signature.