The California Nurses Association has taken on powerful people before, including Gov. Arnold Schwarzenegger and legislators from both major parties, and has scored resounding wins. In each showdown, the 86,000-person union made full use of its key advantage – the appeal of its members' professions – while pressing hard for policies that benefited nurses. This election year, the union is putting its powers to the test as it challenges its most well-funded opponent to date, billionaire Republican gubernatorial candidate Meg Whitman, who is wasting no time fighting back. That the union is leading the anti-Whitman front so far speaks volumes...