Editor's note: Drew Westen is professor of psychology and psychiatry at Emory University, founder of Westen Strategies and author of "The Political Brain: The Role of Emotion in Deciding the Fate of the Nation." He has been a consultant or adviser to several Democratic candidates, nonprofit organizations and Fortune 500 companies, and informally advised Barack Obama's presidential campaign.
Atlanta, Georgia (CNN) -- Politicians tend to think about how the minds and brains of voters work in one of two ways.
The first is to assume that voters come to decisions on issues like health care reform by carefully examining the data and the arguments and then calculating whether one plan or another better fits their rational self-interest. In this view, a campaign is a debate on the issues.
When you hear (or heard) Democratic strategists dismiss polls showing that the majority of Americans opposed the president's health care plan but support its component parts, this is the model of the mind of the voter they are assuming.
That's why Democrats tend to lose ground even on issues with strong popular support, like health care reform, which was extremely popular during the 2008 election but steadily lost backing over the course of the first year of the Obama administration until regaining some momentum over the past few weeks.
The other way to think of voters is as people who have to be sold on a policy or candidate. They are consumers, not debaters, and they'll walk out of a store that doesn't have attentive salespeople.
How do you sell reform? You tell a consistent story about what's wrong with the system, who broke it and how we can fix it. You evoke not only people's concerns about their interests but their values: fairness, the ability to choose what's best for themselves and their family, security.
You try to get people as passionate as you are, concerned about the security of their care, angry at insurance companies that have been calling all the shots and hopeful that you know what to do about it. And you choose your words carefully, because words carry emotional connotations, and people may not know exactly what's in a bill, but they have a general sense of whether they like it.
This is how Republicans tend to think about politics. And it's how they managed to leave Americans with a bitter taste in their mouths about efforts to reform a health care system that had left virtually all of us one pre-existing condition -- or one cancer requiring treatment that exceeded our annual or lifetime "cap" -- away from medical bankruptcy, no matter how good we thought our insurance was.
While Democrats were listing its characteristics like the side effects on a pharmaceutical ad, using phrases like "universal health care" and "health insurance reform" that don't exactly make your spine tingle, Republicans were describing "Obamacare" as a "government takeover" of our health care system that would "put a bureaucrat between you and your doctor."
In this vision of mind, politics is marketing: It's about branding your product (not something the Republicans did well this time, since they weren't really interested in selling reform) and distinguishing it from the competition -- in this case, warning people that there might be poison in the prescription Democrats were offering (something the GOP did extremely effectively).
But something changed in the past six weeks, resuscitating a policy that appeared dead on arrival after a 14-month wait in the emergency room.
It wasn't the Republican opposition. Republicans told the same story from start to finish, and they plan to tell it to the voters again in November.
What changed is that the White House abandoned -- at least for a time -- a vision of the mind of the voter that is dead wrong based on everything we know about how the political brain actually works.
For a year, while the Republicans were telling a great story about "death panels" and the president's "socialist" agenda (though the president wouldn't even support the "socialist" option of giving Americans the option of buying into Medicare if they preferred it over private insurance), the White House wasn't offering a coherent story.
Precisely what problem the plan was intended to fix seemed to shift from week to week (Was it cost? Or the 46 million people without insurance? Or middle-class people losing their coverage?). And as for the plot, we didn't know until a few weeks ago what the president's plan even was.
Making matters worse, Obama seemed to lack passion about his signature issue. Everything seemed negotiable, as if what mattered was that the bill passed, not what was in it. And the White House used every word in the book you wouldn't use if you wanted to "sell" reform.
Instead of emphasizing that people who work for a living ought to be able to take their kids to the doctor when they're sick -- a value statement that makes clear who the bill was designed to help (people who work for a living and still can't get or afford decent health care, or could lose their insurance if they lost or changed jobs or started a small business) -- the White House talked about "bending the cost curve," another linguistic heart-stopper.
But over the past few weeks, that all changed. The president was now telling a compelling story. This story actually included the villains: Health insurance companies denying life-saving care to people for profits. In speeches journalists described as his most "passionate" since becoming president, he told the story of a woman who lost her life after she lost her health insurance and of a little boy who lost his mother because she couldn't pay for her illness. He seized on an insurance rate hike of nearly 40 percent in California to mobilize populist anger.
And for the first time, the president decided to answer the attacks of his opponents, not just with well-reasoned arguments (which he did) but with attitude. When John McCain started posturing at the president's "bipartisan" summit, the president reminded him that the election was over and who had won. When House Minority Leader John Boehner started rattling off talking points, the president responded with the verbal equivalent of eye rolling and asked whether there was someone who actually wanted to get something done.
The president looked strong, resolute and passionate.
There will be those who say this was just the unfolding of a plan the White House held all along. But that would be revisionist history. The president didn't intend to lose Ted Kennedy's seat to a right-wing politician in a left-wing state who campaigned on being the 41st vote against health care reform.
What message the White House has taken away from the events of the past few weeks remains to be seen. Obama can damn the torpedoes and go full speed ahead, dare the Republicans to vote no on every effort to fix every problem the country faces and pursue the pragmatic (sometimes partisan, sometimes nonpartisan) leadership the American people want.
Or he can return to the "why can't we all just get along?" unilateral bipartisanship that tied him up in knots in his first year, as if Republicans are just Democrats in need of rational arguments.
The opinions expressed in this commentary are solely those of Drew Westen.