The senator’s campaign is working to define ‘democratic socialism’ in positive terms while the president and his allies eagerly portray the Democrats as radical leftists.

Three miles across town, in a Thursday-night rally here, President Trump was eager to talk about socialism, bringing it up in the first two minutes and returning to the theme over and over. This November, were going to defeat the radical socialist Democrats that are right down the street, he blared.
As Sanders closes in on a potential win in Mondays Iowa caucuses and Trump sharpens a general election message designed to portray Democrats as radical leftists, a heated debate is emerging over whether America is ready to embrace at least some aspects of socialism if not a socialist president.
Sanders is portraying his agenda as a modern liberal movement, while Trump wants to conjure images of the old Soviet Union and oppressive foreign leaders such as Nicolás Maduro and Fidel Castro. The president intends to return to the topic during his State of the Union address on Tuesday, according to a senior administration official.
The conflict over socialism is far from settled even within the Democratic Party. Former vice president Joe Biden, one of Sanderss top rivals, alluded this week to Sanderss political affiliation, which critics have long used to portray the senator from Vermont as disloyal.
Pressure on both fronts has prompted Sanders and his allies to mount an aggressive defense of his worldview and clarify his positions in the closing days before Iowa holds the first nominating contest.
Sanderss lead in recent polls has forced members of both parties to more seriously contemplate the possibility of something unusual a Democratic nominee who does not officially belong to the party. Such an outcome could have far-reaching implications in the battleground states that will be fiercely contested in November.
Sanders, the most liberal candidate in the top tier of the Democratic field, has long identified as a democratic socialist, a philosophy he detailed in a speech last year. Democratic socialism means to me requiring and achieving political and economic freedom in every community in this country, he said in June. He often emphasizes the democratic to distinguish it from authoritarian socialism.
Although he is officially an independent, Sanders caucuses with Democrats in the Senate and has pledged to support whomever the Democratic Party nominates for the presidency. But he has distanced himself from party leaders more than his opponents have done, and he has frequently lambasted the Democratic establishment.
His posture has prompted some criticism. Im a Democrat, Biden said Thursday. He says hes not. He says you know, hes not registered as a Democrat, to the best of my knowledge. And Bernie has a different view.
The tension was evident Friday morning at a Des Moines coffee shop where Sanderss wife, Jane Sanders, campaigned for him as he tended to his duties in Washington as a juror in Trumps impeachment trial.
I noticed that just recently, one of our chief opponents in the race started talking about how Bernie isnt a Democrat, Sanders supporter Michael McKinley, 68, told Jane Sanders and her son, David Driscoll.
What do we say when they come right back and they say, Well, hes not a Democrat?  he asked.
Driscoll encouraged party unity. Lets try to keep it as positive as possible, he said.
Jane Sanders offered a more robust defense of her husbands politics.
In Vermont, we dont have party registration, she said. So, you just say what you are. She pointed out that Sanders has belonged to the Democratic caucus for years and was appointed by Senate Democrats to represent them in leadership on two committees.
So, I dont know how else to do it, she said. If he had been in another state, he would have had to register as a Democrat. We cant as a Vermonter.
Still, other lawmakers from Vermont, such as the states other senator, Patrick J. Leahy, explicitly identify as Democrats.
Asked after the event about Trumps attacks on socialism, she declined to engage him.
I dont give President Trump a lot of thought, she said. I think that hes a very dangerous president for our country.
Sanders has sought aggressively to distinguish his brand of socialism from the ideas practiced by oppressive leaders abroad. The sign in the Des Moines campaign office, which was on a wall near supporters making phone calls to caucus-goers Tuesday, said that Sanders wants health-care and education systems, as well as the government more broadly, to be reliable, accessible, and effective.
Thats what he means by socialism,  it concludes.
Sanders campaign officials said they are not focused on labels but on the issues that Sanders has been pushing as he tries to appeal to working-class people. Micah Uetricht, an editor at the socialist magazine Jacobin who canvassed for Sanders two weekends in a row in Iowa, said that no one at the doors he knocked on brought up socialism.
Whats more common is that we talk to someone whos dependent on Medicaid, which brings up a discussion on Bernies record defending those programs, he said.
Polls show socialism remains largely unpopular, though how it plays politically among Democrats remains an open question.
A Fox News poll from December found 57 percent of Americans said they were unfavorable toward socialism while 32 percent were favorable. Fifteen percent said that they couldnt say.
But Rep. Alexandria Ocasio-Cortez (D-N.Y.), a Sanders supporter and fellow democratic socialist, has quickly become one of the most electrifying politicians in the country. The Democratic Socialists of America saw its membership increase dramatically after her 2018 upset primary win.
Advocates say that the world is no longer gripped by the paranoia of the Cold War era and that younger voters are not put off by the idea as their parents and grandparents were.
Sanders is pushing an ambitious policy agenda, including enacting a Medicare-for-all health-care system and a Green New Deal climate initiative, both of which would mean sweeping changes to current laws.
Not all Democrats favor those proposals, which would complicate the Republican pitch if the nominee is someone more moderate than Sanders. Biden, for example, favors expanding the Affordable Care Act, not introducing Medicare-for-all.
GOP officials said they are determined to portray the nominee as too far left, no matter who it is. This strategy reprises what the party did in the 2018 midterms, when it sought to cast Democratic congressional candidates as soft on immigration, crime and other highly charged topics.
Is it going to be Bernie, who has Medicare-for-all, who says, outright, Im going to eliminate private insurance?  said Trump campaign spokeswoman Kayleigh McEnany. Or is it Biden, who has a public option the logical endpoint of that being that private insurance is crowded out?
But the 2018 GOP blueprint was largely unsuccessful. Democratic candidates, mostly running on noncontroversial platforms, flipped dozens of seats, which returned control of the House to Speaker Nancy Pelosi (D-Calif.).
Nevertheless, there were a few key examples of success for the Republican Party. In Florida, where many Hispanic voters have roots in Latin American countries with a history of authoritarian leftist regimes, Andrew Gillum, the Democratic nominee for governor, fell in defeat amid attacks casting him as a socialist.
Some Democrats are concerned that if Sanders is the nominee, the prized swing state may be difficult to pry away from Trumps grip. Democrats have also warned that socialism could be a liability in other battlegrounds.
Over the past year, Trumps campaign has come up with different events and gimmicks aimed at branding the full Democratic field as socialist. Socialism destroys Ohio Jobs. Vote Trump! read a banner flying above the Democratic debate site in Ohio last October.
The attacks serve a dual purpose for Trump: rallying his GOP base and inflaming internal tensions in the Democratic Party, said Republican strategist Doug Heye.
It very smartly drives a very blunt wedge into the Democratic debate in the days leading up to the kickoff for really the whole campaign, he said.
Trump has never specifically defined what he is referring to when he talks about socialism, regularly using the term broadly to discuss Democrats positions on energy, health care, taxes, immigration and more.
This election is a choice between American freedom and Democratic socialism, and in some cases, in my opinion, its worse than socialism, Trump said in one of 10 mentions of socialism during his speech in Des Moines on Thursday. Socialisms a kind word by comparison. The Democrats will lose because America will never be a socialist country.
Trumps own policies, including a $28 billion bailout program for farmers struggling under the effect of his trade war, have led to charges of government intervention in the free market.
During the Iowa rally Thursday, Trump appeared to acknowledge the sensitive nature of the massive bailout, saying that he had to use his words carefully as he described it.
I said to this group of farmers that came in, Subsidy. I used the word subsidy, he said. That was the worst word. Sir, we dont want subsidy! Please dont ever use that word. I said, I wont, I promise. 
David Weigel in Des Moines and Emily Guskin in Washington contributed to this report.