CQ Politics changed its rating of the 3rd Congressional District contest from "leans Republican" to a "tossup" last night, saying "there appears to be little doubt that (incumbent Rep. Dan) Lungren will have to fight to hold his seat." The Gold River Republican is facing a challenge from Democrat Ami Bera, a doctor from Elk Grove who has strong backing from the Democratic Congressional Campaign Committee. Lungren, whose seat is a major target for Democrats, . . .