I remember reading an article somewhere about the Republicans celebrating their success in the 2003 Mayor's race because they won a whole 7% of the vote or so.
Yes, in fact in that election the Green Party's candidate Matt Gonzalez (and now Nader's VP candidate), beat the Republican in the first round. He then won around 47% of the vote in the second round against Democrat Gavin Newsom. The Democratic Party was so scared of Gonzalez winning that they even brought in Bill Clinton to campaign for Newsom.
Something of a misstatement, since local elections in California are nonpartisan. Otherwise, he wouldn't have done half as well.