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If Democratic presidential candidates want to get serious about the existential imperative of defeating Donald Trump’s growing authoritarian menace, they need to stop their exotic appeals to left-wing activists and start formulating positions voters actually like. Elizabeth Warren has an idea like this. It might be the best general-election appeal any of the candidates has devised yet: Raise taxes on the rich to pay for an increase in Social Security benefits.

The average Social Security beneficiary gets a paltry $16,248 a year from the program. Warren proposes to increase that by $200 a month, paying for it with a 14.8 percent tax on net investment income for individuals earning more than $250,000 and families earning more than $400,000. Her pay-for would not only cover the costs of new benefits, but bring in enough extra revenue to extend the Social Security Trust Fund by 19 years.

Raising taxes on the rich? Popular. More than 70 percent of the public, including a majority of Republicans, support that.

Increasing Social Security benefits? Even more popular. A 2014 survey found 86 percent of Americans agree that current Social Security benefits do not provide enough income for retirees, and 72 percent agree we should consider raising future Social Security benefits in order to provide a more secure retirement for working Americans. A poll last year found that two thirds of respondents would be more likely to vote for a candidate who would raise Social Security benefits, with just 18 percent saying they’d be less likely.

Democrats have been racing haphazardly to the left, with Warren often in the lead. Some of their ideas, like moving everybody off employer-sponsored insurance and onto a public plan, are toxic to general-election voters. But some ideas have appeal to the left and to swing voters. This is one of them.

Of all the potential soft spots in the Republican party, Social Security is among the most underrated. George W. Bush’s failed pursuit of a privatization scheme in 2005 was a major cause of his political collapse. Conservatives, seeking to deflect blame from their own ideas onto external forces, preferred to blame his response to Hurricane Katrina for his poor polling. But Bush’s polling was dropping like a stone for months before Katrina struck. By July of that year, his plan to change the system was polling 29–62.

Social Security has largely disappeared as a first-tier issue since then. Trump promised to protect it, using the issue to distance himself from fellow Republicans. But his budget plan would cut $26 billion from the program over a decade. (As a share of its total cost, that is a pittance, but most Americans think any dollar amount ending in -illion is large. Why not let Trump try to explain that $26 billion is not a lot of money?)

The trauma of the 2016 election has left many Trump critics so skeptical of political fundamentals they have failed to discern some basic political realities that allowed Trump to win in the first place. Trump was not a popular candidate, but his opponent was unpopular, too. He neutralized public distrust of his party’s economic agenda by positioning himself to the left on economics, both in substance and style, as an outsider who would threaten insiders and the rich. His failure to keep this promise is a major reason why his polling has stagnated in the low 40s.

And yet the threat that he can reprise his 2016 strategy remains very real. Trump doesn’t have to be popular to win. He doesn’t even have to make his Democratic opponent as unpopular as him in order to win. He just needs to be only somewhat more unpopular than the Democrat, and have his support located conveniently in Midwest swing states.

He is engaging in an array of the lowest tactics that will be brought to bear on any presidential campaign — racist and sexist demagoguery, vote suppression, abusing government authority to pressure independent news media, inviting Russian hackers to intervene on his behalf, and any other dirty tricks he can dream up over the next 15 months. Democrats need to treat the task of defeating Trump as the national emergency it is.

Democrats don’t need to cheat to beat him. But they do need to stop dreaming up blue-sky notions catering to progressive activists and refocus on some ideas with gut-level appeal to persuadable working-class voters. An extra $200 a month in Social Security is just the stuff.