(CNN) President Donald Trump clearly thinks he has a winning argument against Democrats in 2020 and it comes straight out of his Baby Boomer childhood.

Trump and other Republicans have spent the past few weeks arguing that Democrats would rob Americans of consumer comforts like cars and hamburgers, using a definition of socialism that borrows from a time when that ideology -- in the form of communism -- posed an actual existential threat in a nuclear standoff with the Soviet Union.

That's not the world Trump sees. When he riled up the young and conservative activists at this past weekend's Conservative Political Action Conference, Trump brought up "socialism" four separate times with four separate one-liners:

"Just this week, more than 100 Democrats in Congress signed up for a socialist takeover of American health care."

"America will never be a socialist country -- ever."

"If these socialist progressives had their way, they would put our Constitution through the paper shredder in a heartbeat."

"We believe in the American Dream, not in the socialist nightmare."

But Democrats are selling a softer socialism, leaning on government as the solution to soaring health care costs, widening inequality, and a new and more dangerous existential threat -- climate change -- that many fear is literally killing the earth.

Their audience is the portion of the electorate too young to remember the Cold War. Freshman Rep. Alexandria Ocasio-Cortez was born in October 1989, the month before the Berlin Wall fell and two years before the Soviet Union collapsed. This group's view of socialism is in the happy social media dispatches from Northern Europe, where child care is free, almost everyone has a job, health care is provided for and retirement is guaranteed.

Socialism is clearly having something of a moment in the US political discussion thanks to Democrats like Ocasio-Cortez, the main spokeswoman for the Green New Deal and for a more socialist Democratic party that would re-imagine the US economy as a way of combating climate change.

It also stems from the 2016 candidacy of Bernie Sanders, the Vermont independent running a second time as a Democrat on a brashly democratic socialist agenda. Sanders, by the way, is the only person currently running in the Democratic primary who calls himself a democratic socialist. Ohio Sen. Sherrod Brown, who is considering a run, likes to call himself a progressive. Massachusetts Sen. Elizabeth Warren, who like Sanders has a disdain for Wall Street and big banks, has said pretty clearly she considers herself a capitalist.

The question of the Democratic primary may very well end up being how much Democrats want to embrace the label of socialism and whether it will continue to be a dirty word in US politics.

Americans coming of age today and even those who have been voting in recent elections are more likely to have encountered socialism not via Russian communism, which is long gone, but from China's version, which is planted emphatically in the world marketplace, or from Northern Europe, where Sanders likes to points out the governments honor free markets but also take care of their citizens.

In an NBC News/Wall Street Journal poll out Monday, just 18% of Americans had a positive view of socialism, 50% had a negative view and 26% had a neutral view. Capitalism, meanwhile, was the mirror opposite: 50% had a positive view, 19% had a negative view and 25% had a neutral view.

Worse for someone like Sanders is that voters were asked what might make them enthusiastic about a candidate. A "socialist" candidate drew the most skepticism. Four percent of registered voters said they'd be enthusiastic about a socialist candidate. Four! Widening that out, 25% said they'd be enthusiastic or comfortable and 72% said they'd be have reservations or be very uncomfortable.

But there's another important element to consider in terms of socialism. Most of the skepticism about socialism comes from older American generations. Trump's Baby Boomers -- he was born in 1946 at the beginning of the Baby Boom -- grew up under fear of nuclear fallout and seeing the Soviet Union as the main existential threat to the US.

Now, it is their distrust of socialism that Trump is banking on, even as those Boomers embrace the twin US government safety nets of Social Security and Medicare.

Less than a third of voters who are 65 and older have a positive view of socialism in Gallup polling from August 2018. That's remained steady since 2010.

Meanwhile, positive views of socialism among 18-29 year olds -- all born after the fall of the Soviet Union -- are much stronger at a steady 50% or so since 2010. And it support falls with each generation from there -- 41% positive among the general Millennial age group and 30% among the general Generation X age group.

That's important because of how many voters are in those younger age groups.

Voters older than 65 will be about 23% of the electorate in 2020, according to projections from Pew.

Voters born after 1996, Generation Z, will be about 10% of eligible voters in 2020. Millennials will be about 27%.

Generation X, who were born between 1965 and 1980, and so have very real memories of the Cold War, will be about 25% of the population.

Only the very oldest voters might be old enough to remember 1920, the high water mark for American socialism, before the Cold War or the Soviet Union, when Eugene Debs, running outside the major party system, got 3.4% of the US presidential vote as a socialist.

So maybe Sanders' honeymoon in the Soviet Union in the 1980s won't lead to conspiracy theories about him as a Manchurian Candidate of sorts. Especially since it is the new Russian plutocracy of oil barons and oligarchs that interfered with the 2016 election in an attempt to help Trump.