For a job that supposedly means so little, a lot of people seem to really want it. L.A. Councilwoman Janice Hahn and San Francisco Mayor Gavin Newsom may be running for a job often derided as politically impotent, but the Democratic race for lieutenant governor is turning out to be one of the most spirited — and perhaps nastiest — of the primary season. It all started when Hahn’s campaign consultant, Garry South, took shots at his former client, Newsom, for entering the race last week. Now, Hahn is trying to put a damper of Newsom’s fundraising, arguing that donors who have given to Newsom’s campaign for governor should be barred from giving to his lieutenant governor’s campaign. In a complaint filed with the Fair Political Practices Commission on Tuesday, Hahn’s attorneys argue that Newsom donors who have already contributed more than $6,500 when Newsom was running for governor should be barred from giving again. Newsom spokesman Jason Kinney called the complaint “one of last Hail Mary acts of a flailing campaign,” and Newsom’s campaign responded with a lawyer’s letter of his own, from attorney Tom Willis. “Janice Hahn’s complaint to the FPPC ignores two important things: the law and the fact the FPPC has already rejected her argument,” Willis wrote.