Have you heard that Elizabeth Warren has an ambitious plan — a surefire popular plan — to boost Social Security payments by roughly $200 a month?

Amazingly, the details she unveiled last week never came up in the Democratic debate on Thursday night. Which was a shame, because this proposal could help her draw older voters away from Joe Biden, and — if she were the 2020 nominee — it could work the same magic in a showdown with Trump.

Without getting wonky, here’s the gist: She wants to take from the rich and give to the middle class and the needy. She wants to finance the $200-a-month Social Security hike by slapping a 14.8 percent tax on the net investment income of individuals who earn more than $250,000 a year, and families that earn more than $400,000 a year. Right now, Social Security is funded by a flat-rate payroll tax (half of which we pay, half of which our employers pay) that’s capped at $132,000 of a worker’s income. Investment income garnered by the rich isn’t touched at all.

Warren’s idea would put so much fuel in the Social Security tank that not only would the average recipient get an extra $200 a month, it would also extend Social Security’s solvency from the currently projected 2035 to 2054. What’s not to like?

Granted, this progressive idea would be DOA in the Senate if Mitch McConnell remains in charge after the 2020 election — and, thanks to a GOP filibuster, it would likely die even if Democrats win the White House and Senate. But unlike some of the politically suicidal ideas currently being circulated by Warren, Bernie Sanders, and the longer-shot progressive candidates (erasing private health coverage, decriminalizing illegal border crossings), a Social Security boost is at least a political winner that would help oust Trump.

As Democratic strategist Ruy Teixeira says on Facebook, “Taxing the rich: Popular! Increasing and expanding Social Security benefits: Popular!” That’s what the polls say. This is a left-of-center issue that the center likes a lot.”

And if you question whether Social Security (the “socialist” program created during the New Deal, over vociferous Republican opposition) is broadly popular, remember what happened when newly re-elected George W. Bush decided to use his political capital to pitch a partial privatization plan in 2005.

As I wrote at the time for The Philadelphia Inquirer: “The longer Bush stayed on the road talking up partial privatization, the more people got turned off to the idea. The more he tried to explain it, the more confused people became” — and the lower his approval rating fell. People didn’t trust the Republicans’ idea of exposing Social Security to the vagaries of the free market.

Here in 2019, Warren can potentially tout her Social Security plan to peel a sizable share of older Democratic voters away from Biden. As a CNN analysis recently reported, voters over the age of 45 dominated the 2016 Democratic primaries — casting roughly 60 percent of the ballots. And looking ahead to the general election, lest we forget (and try not to gag) that Trump arguably won last time in part because he scored solidly with the older electorate — winning 52 percent of voters aged 45 and higher.

As we know, a huge share of the electorate is predisposed to hate the Democratic party. But Social Security is solid Democratic turf. Dissing the program has been part of the GOP’s DNA ever since it was created in 1935. As New Jersey Republican Senator A. Harry Moore warned that year, while urging Congress to vote no, Social Security “would take all the romance out of life. We might as well take a child from the nursery, give him a nurse, and protect him from every experience that life affords.” Seventy-five years later, GOP presidential candidate Rick Perry called Social Security “a Ponzie scheme.”

The road to ousting Trump and saving democracy can start with this issue. Democrats need to own it anew, and Warren’s plan could make it happen.

Dick Polman, a veteran national political columnist based in Philadelphia and a Writer in Residence at the University of Pennsylvania, writes at DickPolman.net. Email him at dickpolman7@gmail.com.