FORTUNE — There’s not much in the way of suspense here in Tampa. Mitt Romney has effectively owned the nomination since the primary season wrapped up in the spring. We’ve known the identity of his running mate, Wisconsin Rep. Paul Ryan, for weeks. What Americans are seeing broadcast from the stage of the Tampa Bay Times Forum this week has all the spontaneity of a dramatic reading of the phone book.

But for a (very) brief moment on Tuesday afternoon, the convention floor felt like a relic from the time when ward heelers and party bosses prowled the halls. Supporters of Texas Rep. Ron Paul — the iconoclastic libertarian with a fiercely loyal following — erupted into chants of his name, before Romney backers shouted them down. It was a last gasp of a gadfly campaign, as Paul supporters launched a final protest against party rules changes they say denude the grassroots.

And while most of the rank-and-file here regard the Paulites as an oddity, wandering the convention floor, there was also an unmistakable sense that Republicans are at least as motivated by ousting Obama as they are by installing Romney.

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Among registered voters, Obama still enjoys a 6-point edge over Romney on the question of whose voters are the most enthusiastic. It’s a stat borne out by conversations with delegates, many of whom settled with Romney after their first choices flamed out in the primaries. Peggy Hudson, of Marrietta, Ga., declared herself a big Romney fan and talked up his business bona fides as evidence he can captain an economic turnaround. But as she kept talking, it became clear that abortion is the issue closest to her heart. She started out backing Newt Gingrich, a hometown hero, and accommodated herself to Romney in the hopes the party’s conservative base will steel his spine on social issues he’s wobbled on over a decade in public life. “We’ll just have to wait and see on that,” she said.

George Engelbach, a former state legislator from Hillsboro, Mo., backed Newt, then former Pennsylvania Sen. Rick Santorum before landing on Romney. Stalking the convention floor in an Abe Lincoln costume, complete with stovepipe hat and chinstrap beard, he was hard to miss. “I love the ticket,” he said, but he also harbors reservations about how Romney would approach a Supreme Court nomination.

One of the younger faces in the crowd, 25-year-old Brian Dougherty, sported a “Goldwater ’64” button on his sport coat. A Paul supporter not yet ready to rally to Romney, he warmed up for the convention by watching videos of the 1964 and 1976 conventions, both of which featured pitched fights between conservative activists and the GOP Establishment. “In the long run, it strengthened the party,” he said, despite the fact that Republicans lost both contests.

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There was no shortage of full-throated Romneyites, either. Peter Beck, a state legislator and accountant from southwest Ohio, unspooled a familiar list of arguments for the candidate — “business owner,” “knows how to create jobs,” “knows what it’s like to sign the front of a paycheck” — to explain why he’s backed him all along. The balance are winding up to join the cause because they’ve got an enemy in common. Channeling Lincoln, Engelbach issued a warning to President: “I think he better start saving my pennies.”