Sen. Sheldon Whitehouse is stopped just outside the Senate floor talking about climate change, as he's known to do. He hasn't slept, coming off an all-nighter on climate change in which more than two dozen Senate Democrats held the floor.

The Rhode Island Democrat is discussing why he's heading to Iowa and Nebraska for a three-day trip Monday to push action on climate change. Iowa, which hosts the bellwether poll of presidential hopefuls, is symbolic, though Whitehouse has no plans for that office. ("I'm going to be for Hillary — always have been.")

But his trip does have presidential motives. Not even two years after activists struggled to insert climate change into the presidential race -- they criticized both President Obama and GOP candidate Mitt Romney for their silence on it -- Whitehouse and Senate Democrats are starting early.

"It's to point out that in this battle for public opinion, we have the better side of the argument by a mile," Whitehouse said.

Before Whitehouse can finish, Sen. Orrin Hatch comes up from behind, putting both hands on his colleague's shoulders. "Don't believe him," the Utah Republican says through a smile.

That, really, is why Whitehouse is heading to the heartland.

An overwhelming scientific consensus, on par with the certainty that smoking cigarettes causes cancer, says humans drive climate change mainly by burning greenhouse gas-emitting fossil fuels. But many congressional Republicans are skeptical of or deny that.

"Simply putting light on it will move people more in our direction because the other side is in a completely incredible place," Whitehouse said. The goal, he said, is to get the public to demand an eventual, sweeping climate bill — the last one fizzled in the Senate in 2010 after it passed the House — or to vote to send like-minded politicians to Washington.

That's what many Democrats are betting, anyway. And they're getting some help from big donor Tom Steyer, a climate activist and billionaire former hedge fund manager who has pledged to put up $50 million of his own money in the 2014 midterms. He has asked other donors to match that and is likely to play a role in the 2016 races.

But the question remains: Can climate change play in Iowa, Nebraska or other states generally cool to the topic?

"For average people out here, I think climate change is a fairly abstract notion," said Dennis Goldford, a politics professor at Drake University in Des Moines, Iowa. "I think you have for people out here a more concrete, meat-and-potatoes set of concerns."

Jobs, the economy, the deficit. That's the stuff political winners are made of in Iowa — even for the state's independent voters, which Goldford puts at 37 percent, with the remainder about evenly split between Democrats and Republicans.

That same dynamic is at play for Senate Democrats up for re-election in red-leaning states. Sens. Mary Landrieu of Louisiana, Mark Pryor of Arkansas, Mark Begich of Alaska, and Kay Hagan of North Carolina didn't participate in the overnight climate event on the Senate floor.

Still, experts say Iowans are beginning to realize climate change is a fact.

In the past two years the agricultural sector, which comprises about 30 percent of the state's economy, has withstood near-record drought, increasingly frequent floods and a harsh winter that decimated profits. And Iowa early on embraced corn-based biofuels, seen as a way to reduce greenhouse gas emissions.

"Climate change is costing farmer[s] money and they know it," said Eugene Takle, director of the Climate Science Program at Iowa State University in Ames. He added that the shift to accepting climate change has been "gradual," but that it could be a winning issue for Democrats because they've "been more consistent in accepting the science."

Senate Democrats appear to be banking on that.

"If we do our work at making this a public issue, people will naturally move to the sensible position," Whitehouse said. "We're in a weaker position than we need to be because we've allowed the denial argument to go unanswered when it is essentially preposterous and easy to answer."