The two-week convention caravan is now at rest, and Tampa and Charlotte are in the rear-view mirror. So how did the two conventions compare, seen up close and side by side? Well, sometimes stereotypes ring true: Republicans fall in line, while Democrats fall in love.

Conservatives are primarily united by the prospect of unseating President Obama, while at least among liberal conventioneers the love affair with him still seems to be going strong.

On the airwaves, this is a definitively post–Hope and Change election, with both campaigns trying to motivate their base by any means necessary to vote against the other guy. Positive pitches or policy plans have been basically MIA on television, where most Americans are viewing the campaign.

The nomination of Paul Ryan has invigorated Mitt Romney’s appeal among the base and strengthened his campaign’s policy credentials, for better or worse. The carefully selected center-right convention speakers—otherwise known as the 2016 bench—criticized President Obama with a studious sadness, a script aimed at giving disaffected centrist voters permission to give their team a chance.

But there are limits to the appeal of an essentially negative agenda—kicking the other guy out rather than rallying around the prospect of President Mitt Romney. As the anemic one-point bump out of Tampa shows that enthusiasm hasn’t yet spread to swing voters.

The contrast in Charlotte, N.C., was clear: convention-going Democrats are motivated to vote for their candidate rather than just against the other guy.

Covering this election, the optimism of the Obama 2008 campaign is hard to conjure up. If, as Mario Cuomo said, “you campaign in poetry but govern in prose,” the prose offered by the Obama administration has been uninspiring—especially against the backdrop of a still-sluggish economy. President Obama’s sober-rather-than-soaring nomination speech essentially conceded that fact.

But walking around the Charlotte convention, I was struck by the copious grassroots Obama iconography—not slick, super-PAC sponsored imagery, but the small-press series of T-shirts and buttons, paintings, posters, and children’s books.

There were posters testifying to the enduring Obama, calendars, and apparently self-published children’s books—I Can Be Anything I Want To Be. T-shirts of the kind that sprout up at rock concerts riffed off of Clint Eastwood (“This Seat Is Taken”), and a list of “Obama Top 10 Achievements (So Far)” was punchy enough that the White House communications shop could learn a thing or two from it. There were one-of-a-kind oil paintings of the president and limited-edition prints showing Obama alongside Martin Luther King Jr., Nelson Mandela, and Malcolm X. The most gonzo imagining of the president and first lady showed them riding on horseback Magnificent Seven style alongside King, Muhammad Ali, and Bob Marley, along others. There was a giant sand sculpture of the president and even an art gallery hosting afterhours parties with half its inventory being abstract impressions of the Obamas (in addition to a giant bottle-cap mosaic of Jackie Kennedy). There was even a $7 CD with “The Obama Shuffle.”

The cumulative effect was surreal and occasionally silly, but not creepy—it did not stray into cult of personality as much as reflect heartfelt fandom. It has an obvious relatable parallel—the love of the Irish Catholic community for JFK. Just as he was their first president, Obama will always hold a similar place in the firmament for the African-American community, a place where pride and patriotism intersect and inspire future generations into public service.

It follows then that the other clear point of contrast was the diversity difference between Tampa and Charlotte.

Republicans were careful to put forward a decidedly diverse set of prime-time speakers—including Marco Rubio, Brian Sandoval, Susana Martinez, Nikki Haley, Ted Cruz, and Artur Davis, among others. Contrary to stereotypes, Republicans actually boast a more diverse set of governors than Democrats right now—and that is significant. But the delegates were disproportionately white, older, and wealthy—even more so adding the donor class to the equation.

Among Democrats, the delegate diversity was probably above national averages at this point, but the diversity in ages and incomes, in addition to race and ethnicity, was also apparent. Demographics are destiny, and the Democratic convention looked a lot more like America in the 21st century. This is not a news flash, but another reminder of the significant outreach Republicans are going to have to do, not just in terms of candidate recruitment but constituency outreach going forward.

Overall, the Obama iconography stood out as not just interesting but significant, because it is almost impossible to imagine Mitt Romney inspiring that kind of grassroots passion. Put easy jokes about the “Romney Shuffle” aside and reflect on the fact that you can’t buy love.

Bottom line: the Democrats did a lot to help shrink the enthusiasm gap at their convention last week, but it wasn’t just the speeches by the first lady, Bubba, and Biden. The candidate himself is still a historic figure who, even brought down to earth by the realities of governing, inspires many people in a way that average politicians don’t. Positive tends to defeat the negative.

In a close election, the Obama cool factor ads a little bit to the election arithmetic.