After five days spent driving around Iowa, meeting with political activists, consultants and regular voters, one thing is clear: the 2016 presidential campaign is on — at least on one side.

Nine GOP Men, One Stage, Six Hours

Over the weekend, there was what can only be described as a Republican cattle call: 900 people and nine potential presidential candidates packed into a large hall at the state fairgrounds for the Iowa Ag Summit. On stage, Chris Christie, Jeb Bush, Mike Huckabee, George Pataki, Rick Santorum, Lindsey Graham, Ted Cruz, Rick Scott and Scott Walker fielded questions about farming, trade and, of course, ethanol.

Six hours later, the not-officially-declared but all but certain GOP hopefuls were on the road, for meet-and-greets and various campaign-style events. For former Florida Gov. Jeb Bush, the destination was a Pizza Ranch restaurant in Cedar Rapids.

When people considering a presidential bid start showing up at Pizza Ranch restaurants, there's only one reasonable conclusion: The campaign season has begun (even if the lakes are still frozen).

Bush already has hired a top Iowa political consultant to run his eventual campaign, and he's far from the only Republican scooping up staff, reserving office space and building enthusiasm among Iowa GOP activists.

For self-described "whoohoo girl" Joni Scotter, this is a little bit of heaven. She has already met most of the GOP candidates, including Bush, who gave her a hug Saturday night at the Pizza Ranch.

"We've got so many candidates out there that are so exciting and they take my breath away," says Scotter.

For The Democrats, It's Crickets ... So Far

I drove out to Council Bluff, Iowa, in the far west of the state, to have lunch with Linda Nelson — the Pottawattamie County Democratic Chair, a retired elementary school teacher with a surprisingly salty vocabulary.

There are at least two reasons she had time for lunch with an out-of-town reporter. One, she's retired. And two, there's not a whole heck of a lot going on when it comes to campaign activities.

By this time in the cycle, you'd expect to see candidates making the rounds, but there has been very little of that so far.

She's getting a lot of questions from her fellow Democrats: "Who's in and where are they and how soon are they coming," she says.

Of course, the really big question is if or when Hillary Clinton will say she's running.

"You know the big elephant in the room, the nose not yet under the tent yet, is Mrs. Clinton," says Nelson.

Behind the scenes the former first lady and secretary of state has been bringing on staff. Her people are making calls, and operatives here expect a campaign infrastructure to pop up soon. But for the local activists like Nelson, it has just been a lot of watching and waiting and reading unflattering stories about emails and foreign donations to the Clinton Foundation.

"With her not making an announcement — not giving us a direct signal that she will be running — then others are, as we know, not getting in, and so it's just holding up the whole process," says Nelson, before turning to the real reason this is a concern. "As a county party chair, this is how we build our party."

The party uses events with candidates to raise money and recruit volunteers, who during the general election will make calls and knock on doors. Now, they talk wistfully about the electricity of 2008. There was a whole crowd of serious democratic contenders competing for their attention. One county party chairman told me that by this time in 2007, he'd already met Barack Obama, twice.

Vermont Sen. Bernie Sanders is holding events, but he's not even really a Democrat. Former Maryland Gov. Martin O'Malley has one operative on the ground in Iowa and four events in the state scheduled over the next month.

Copyright 2016 NPR. To see more, visit http://www.npr.org/.