This is the final four weeks of a national taste-test in which two men, two parties, and two brands square off.
Advertising executive Linda Thaler knows a little something about this.
She produced ads Burger King used to take on McDonalds, and films Bill Clinton used to win the White House.
"The Bush brand was very clear. 'You may not like my decisions but I stick with them and I stay the course,' as his dad used to say," says Thaler.
In this voters-as-consumers model - Bush/Kerry as Coke/Pepsi - any advertising pro knows the key: To sell a product, link it to a larger, subliminal message. Not about the product, but what choosing it says about the buyer.
"Everybody wants to be associated with a winner. The reason people bought Nike sneakers is because they saw Michael Jordan. And they wanted and identified with this brand. The sneakers were a very small part of it," says Thaler.
Maybe John Kerry's rough couple of months is as simple as that: He had no brand - he was offering up nothing beyond not being George Bush. Not only did that get a little thin, it also left him wide open because rule number one of marketing is: If you don't establish your own brand - your competition will do it for you.
"Kerry's biggest mistake was allowing Bush to brand him before he branded himself," says Thaler. "Before he was allowed to say who he was, Bush was out there saying, 'You know who you are? You're someone who flip-flops. And I have a pair of sandals to prove it.'"
On Thursday, Kerry took a couple of important steps toward establishing his own brand - his first steps toward giving voters a sense they have real choice - and perhaps he started re-branding his opponent.
If John Kerry did anything Thursday night, it was to shake up the national karma. How much? Too soon to say, but clearly, he's at least rolled out the idea to voters they can consider another brand, and feel good about it.
"People want to vote for the person that they think is the winner. And if the general karma of the country is negative about a candidate - 'Well, I don't want to cast my vote for somebody who's a loser,'" says Thaler. "Oddly enough, the way you know when the national karma starts to change is the next morning when you go to work. You walk in, and somebody says, 'Hey, you know, Kerry was pretty good last night.' 'Yeah, I always thought he was pretty good.'"
But there's a gulf between considering another brand and actually buying it. Every time Pepsi tries something to cut into market share, Coke counters. Don't expect either man, or either brand to sit still during this last month until check out time.