In these polarized times, liberals and conservatives tend to talk past each other. Leftists tend to envision a brighter future, while right-wingers lovingly look to a more-perfect past. "Forward," urged Barack Obama. "Make America Great Again," replied Donald Trump.

Here's a thought: What if we could decouple those deep-seated propensities from actual policy positions? Specifically, what if liberals advocated for a progressive platform by evoking conservatives' nostalgia for a romanticized bygone era?

Two researchers tried it—and found the approach markedly decreased conservatives' resistance to liberal ideas. Amazingly, this held true even when dealing with such hot-button issues as immigration and guns.

"Conservatives prefer policies that appear to be grounded in the past, and this strongly influences their support for political ideas," write University of Cologne psychologists Joris Lammers and Matt Baldwin. This insight, they add, creates "an opportunity to more effectively communicate liberal political issues across party lines."

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"A large portion of the political disagreement between conservatives and liberals appears to be disagreement over style, and not content," they write in the Journal of Personality and Social Psychology.

Conservativism has been called the "politics of nostalgia" since at least 1955, the researchers note. Those on the right, they write, "have an intuitive preference for political ideas that contribute to maintaining society how it was and has been."

More often than not, that translates as support for policies liberals consider regressive. But in a series of studies, Lammers and Baldwin show it can be used to very different ends.

One online study featured 200 Americans who read one of two statements advocating a more permissive form of policing. One framed this as a desirable vision for coming years, writing: "I can see a shift happening so that police will be more lenient."

The other portrayed it as a return to older, simpler times, writing that, "in the old days," if you were publicly drunk, "the police would not immediately book you, but instead just give you a warning. I would like to go back to how things were then." Participants expressed their level of agreement or disagreement with whichever statement they read.

"The disagreement between liberals and conservatives about a message calling for greater leniency in criminal justice was strongly reduced—to the point of statistical indiscernibility—if the message was focused on the past, rather than on the future," the researchers report. "We found this effect in both a U.S. sample and in a replication in the U.K."

A similarly structured study, again featuring 200 Americans, focused on gun rights. Half the participants read a statement advocating a change in the law "so that in the future, people may own hunting rifles and pistols, but no one will have assault rifles." The others read one that stated "I would like to go back to the old days, when people may have owned hunting rifles and pistols, but no one had assault rifles."

The result: "The degree to which liberals and conservatives disagreed about a call for increased gun control was greatly reduced if the message drew comparisons with the past, instead of pointing to the future."

A follow-up study conducted in Germany found disagreement between people on the left and right over immigration narrowed considerably if the text they read focused on the past (for example, noting that Germany has welcomed immigrants throughout its recorded history).

Finally, another study used the aforementioned law-enforcement-leniency arguments to see if a future focus would similarly increase liberals' support for conservative ideas. The researchers report it did not, apparently because liberals do not "intrinsically value the past over the future."

Which should make a shift in rhetorical style easy to implement.

So, liberals, if you're trying to convince conservatives of the need for change, don't paint a picture of a fairer future; that will only appeal to those already in your camp. Rather, try framing it as a return to a long-lost American ethos that needs to be resurrected.

Given how effective that can be, we may find ourselves traveling back to the future.