(CNN) As Americans gas up for the start of the summer driving season, they'll pay the highest Memorial Day prices at the pump since 2014 . And they'll have trouble finding any sort of middle lane in the oil wars of American politics.

Voters in 2020 can choose President Donald Trump, who brags about oil production -- the fact that the United States is now the largest producer of oil on Earth

Or voters can opt for the Democratic presidential candidate, whoever it ends up being. All of them agree that humans contribute to climate change -- which is nearly universally described as an existential threat -- and that the US must do something about carbon emissions immediately.

Partisan split

Nearly every Democrat or Democratic-leaning voter -- 96% in a CNN poll in April -- wants a candidate who will take aggressive action on climate change.

It's a far less important issue for most Republicans. An NBC News poll in December found 71% of Democrats saying climate change required immediate action compared with 15% of Republicans.

That's an incredible split that suggests about half the country believes that the world is on pace for a climate reckoning and the other half is basically meh.

Climate change history

More than 10 years ago, the last time they controlled Congress, Democrats passed a plan through the House of Representatives that would have put a price on carbon emissions. It doesn't get much discussion now, since it died in the Senate, but at the time it was thought to be just as responsible for their 2010 election loss as Obamacare

Do nothing

Oil and other kinds of energy of the carbon-emitting variety are, according to Trump, central to the strong economy. And the strong economy is central to his reelection prospects.

"By unleashing American oil, natural gas and clean coal, workers like you are helping to fuel America's historic economic boom. And that's what it is," he told oil workers, arrayed behind him in white hard hats, during an event last week in Louisiana

He's pushed offshore drilling, eased the way for pipelines that carry oil from shale and has a new plan to further and dramatically expand fracking in California

Do something huge

There are variations on the Democrats' theme of climate change action.

Washington state Gov. Jay Inslee has built his entire campaign around the issue of climate change and the Democrat's recently signed a ban on fracking in his home state. As president, he'd move aggressively toward electric cars, carbon-neutral power plants and more efficient buildings a la the Green New Deal

He wants to build an entirely new economy to combat something that poses such a threat to humanity.

Do something

would raise $3 trillion in new revenue over time. Much of that money would be given to states, perhaps gaining some GOP support. But he'd use some of the proceeds to invest in renewable energy research. John Delaney, a Maryland congressman, is the latest Democratic presidential candidate to release a climate change plan . He'd impose a fee on carbon emissions, which he sayswould raise $3 trillion in new revenue over time. Much of that money would be given to states, perhaps gaining some GOP support. But he'd use some of the proceeds to invest in renewable energy research.

He argues that his plan is more feasible than those of some of his Democratic counterparts pushing more drastic proposals. Appearing on MSNBC on Friday, Delaney said that is the difference between him and Inslee.

"Yeah, my plan is better than his because it can get done," he said. "It is big, it responds to the challenges and I can get it done, and I have already shown how I can get the cornerstone of my plan done in the Congress."

Bold ideas, and less so

Some, like Sens. Bernie Sanders of Vermont and Elizabeth Warren of Massachusetts, would ban fracking in the US altogether.

Sanders renewed his call to end fracking with a disturbing video shared to his social media accounts earlier this month about the rise of earthquakes in Oklahoma

Whether that is feasible in states that have embraced fracking would be a very difficult question for them to answer.

Some candidates are finding it hard to live up to the standards they set for themselves or that climate change activists demand. Former Texas Rep. Beto O'Rourke has mentioned the "existential threat" of climate change, but the Texas Tribune documented how he ran afoul of some environmental groups during his 2018 Senate campaign when he took contributions from people who work in the oil and gas industry after signing a pledge not to take money associated with fossil fuels.

Democratic Sen. Amy Klobuchar of Minnesota has rejected the Green New Deal proposal as aspirational, but she said at a CNN town hall in February that addressing climate change would be a top priority for her.

"I don't think we are going to get rid of entire industries in the US," Klobuchar said then.

Mocking renewable energy

Trump is on the complete opposite end of the spectrum. His plan to increase offshore drilling around the country has hit a snag with a recent court decision in Alaska.

He's hostile to investment in offshore wind turbines that deliver renewable energy. He fought, unsuccessfully, against such turbines off the coast of a golf course he owns in Scotland because they would ruin the view. And he's mocked wind energy as unreliable.

He placed tariffs on solar panels coming from China, a move that has led to lost jobs in that renewable energy industry even as he tries to prop up the coal industry.

Voters will decide

Just as Trump's climate change denials led him to isolate the US by withdrawing from the Paris climate accord , any Democrat who beat him in 2020 would, presumably, jump back in immediately, an epic whipsaw.

Ultimately in 2020, if it's an election decided in the middle, the question that will be answered is whether the country will do something about climate change or nothing at all.