Here is the challenge for presidential candidate Bernie Sanders: He has long described himself as a Democratic socialist. A Gallup Poll earlier this year found only 47 percent of Americans said they would vote for a socialist for president. More people said they would support an atheist, a Muslim or a Mormon.
Asked during last month's Democratic debate how a socialist, of any kind, could be elected president, the Vermont senator said, "We're going to win because first we're going to explain what Democratic socialism is."
And so, Sanders is set to give a big speech Thursday explaining just what he means by Democratic socialism.
Think socialism and you may think of the government taking over the steel mills and the oil refineries — the means of production. That's not what Sanders has in mind. But he does envision a greatly expanded role for government.
Sanders is calling for things like Medicare for all and free public college paid for by higher taxes on the wealthy. He'd do some redistribution of wealth. But he's thinking modern day Denmark — not 1950s USSR. Still, when you say socialism, many people think of Marx and Lenin.
"Bernie Sanders is taking on an uphill fight, but he's trying to change the definition of a basic word," says Kathleen Hall Jamieson, director of the Annenberg Public Policy Center at the University of Pennsylvania.
"Every program that conservatives haven't liked for the past 40 years has been identified as a socialistic program and no one has been standing up to defend socialism," adds Jamieson. "In effect the word has taken on very negative connotations because no one has taken the time to define it differently."
But the very viability of Bernie Sanders' candidacy depends on whether he can take the word back, give it new meaning. And his Democratic socialism speech is part of that. There's a history of big political speeches designed to take on and neutralize a lingering concern of voters.
Here are four speeches Sanders might use as a model for his address:
John F. Kennedy on his Catholic faith:
In 1960, John F. Kennedy, who was Catholic, faced questions about whether he would take orders from the Vatican if he were elected president. He tackled the issue head on in a speech to a group of protestant ministers called the Greater Houston Ministerial Association.
"I am not the Catholic candidate for president," Kennedy said in a key line of the speech. "I am the Democratic Party's candidate for president, who happens also to be a Catholic. I do not speak for my church on public matters, and the church does not speak for me."
Mitt Romney's "Faith In America" speech:
As he ran for president the first time, Mitt Romney felt compelled to explain his Mormon faith. Romney was a leader in the Church of Jesus Christ of Latter-day Saints and spoke about his faith and religious freedom in a speech at the George Bush Presidential Library.
"I will put no doctrine of any church above the plain duties of the office and the sovereign authority of the law," Romney said in the address.
President Obama's speech on race
Then-candidate Barack Obama gave a speech about race relations in America in March of 2008 at the Constitution Center in Philadelphia. Obama, who would become the nation's first black president, was compelled to address matters of race after video surfaced of his pastor, Jeremiah Wright, disparaging white America.
"The fact is that the comments that have been made and the issues that have surfaced over the last few weeks reflect the complexities of race in this country that we've never really worked through, a part of our union that we have not yet made perfect," Obama said.
These speeches follow a pattern. This is me. This is why you shouldn't be concerned. And this is why you should feel good about electing me. But the analogy for Sanders is imperfect, says Jamieson. She suggests a better one might be a speech from 1964 by Ronald Reagan.
Reagan's "A Time For Choosing"
Reagan wasn't running for president. He was an actor and pitch man who had been enlisted by the campaign of Barry Goldwater to make a case for the republican nominee. And Reagan used the speech to reclaim conservatism.
"Somewhere a perversion has taken place," Reagan said in the televised speech before a live audience. "Our natural unalienable rights are now considered to be a dispensation of government and freedom has never been so fragile, so close to slipping from our grasp as it is at this moment."
Watching this speech is to see the early threads of today's conservative movement.
In many ways, the Reagan speech is a mirror image of what Sanders aims to do with his speech. It's not about identity. It's about ideology and a view about the size and role of government in American life. Reagan thought it should be smaller. Sanders thinks the role of government should be much larger. And like so many elections before it, that is likely to be one of the defining debates of this contest.