City Comptroller Bill Thompson is clearly banking on a tortoise-and-hare approach to beating his billionaire rival, incumbent Michael Bloomberg, in this year’s mayoral race. Though he has $5 million in the bank, he’s not planning on sending out any campaign literature in the near future, and has aired no television ads to match Bloomberg’s seemingly constant stream of spots. His only hope, he told the Times, is to save up his money and energy for an all-out assault leading up to Election Day. “To try to go toe to toe with the mayor makes no sense,” he said . “There is no way we can compete on TV and radio.” Instead he’s been attending three to four small meetings in union halls every night and testing his messages. He’s hoping to sail through the primary (his only opponent at the moment seems to be cash-poor City Councilman Tony Avella) and then go on the attack in the fall. His inspiration, he says, is the Philadelphia mayoral bid of Michael Nutter, who won a surprising Democratic primary at the last minute in 2007. In fact, Thompson hired a pollster and political consultant who worked on that campaign. “Little by little, Nutter peaked at the right time,” Thompson told the Times. After the primary, Nutter also faced off against a Republican billionaire, and won — though the similarity ends there. His foe, Al Taubenberger, was an aspiring Republican politician who was best known at the time for losing two congressional runs — not, unfortunately, an incumbent mayor with strong job-approval ratings.