Whole Foods ( WFMI) CEO John Mackey should stick to selling healthy foods, rather than health care plans, if he wants to avoid irrational union headaches. A group of unions responded Tuesday to a Wall Street Journal opinion piece on health care written earlier this month by Mackey by demanding his resignation. The CtW Investment Group, a part of the Change to Win federation of unions that advocates on behalf of workers' investments in pension funds, said it is calling on the Whole Foods board to remove Mackey as chairman and find a new CEO. In a statement, CtW Investment Group's Executive Director Bill Patterson accused Mackey of attempting to "capitalize on the brand reputation of Whole Foods to champion his personal political views, but has instead deeply offended a key segment of Whole Foods consumer base." Also on the attack, the United Food and Commercial Workers Union said Mackey's op-ed was an "attempt to undermine Obama's health-care reform" and will be distributing its own health care propaganda to Whole Foods shoppers. It's worth noting here that Whole Foods is not even unionized. But that's only part of what makes this entire episode bizarre. As far as we can tell, these groups just want to muzzle Mackey, whose platform, especially compared to his wild blogging exploits, is politically conservative but definitely not wacky. Most of all he worries about the "hundreds of billions of dollars of new unfunded deficits" that would move the country "closer to a government takeover of our health-care system." Basically, nothing we haven't heard yelled at a congressman in a raucous town hall meeting. Even if you disagree with him, Mackey is offering his ideas civilly and, as Whole Foods shoppers would certainly appreciate, organically. It's the unions who need to get it together. Dumb-o-meter score: 85 -- Kroger (KR) management enters the Middle East debate at its own peril.