Newly elected Democrats in the House of Representatives spent June 27 with the sinking feeling that it was happening again: Their party was going to cave to President Trump and Senate Majority Leader Mitch McConnell (R-Ky.) on a viscerally emotional issue. Just after a searing photo circulated of a father and his young daughter who had drowned in each other’s arms while fleeing for the sanctuary of U.S. shores, Democrats in Congress let a GOP-drafted spending bill go through that did nothing to address conditions for detained immigrant children — abandoning a House version that would have ordered improvements. House leaders blamed Senate Democrats for capitulating; Senate Democrats attacked the House for poor negotiating.

The new insurgent class of Democrats put the fight in sharp moral terms. “A vote for Mitch McConnell’s border bill is a vote to keep kids in cages and terrorize immigrant communities,” said Rep. Ilhan Omar (Minn.). “If you see the Senate bill as an option, then you don’t believe in basic human rights,” declared Rep. Rashida Tlaib (Mich.). “Hell no. That’s an abdication of power,” said Rep. Alexandria Ocasio-Cortez (N.Y.).

Frustration with the refusal to stand up for principle is boiling over among younger Democrats. On issue after issue — impeachment, Medicare-for-all, a $15 minimum wage, free public college, a Green New Deal — the answer from House Speaker Nancy Pelosi (Calif.) and other Democratic leaders is consistent: Now is not the time; the country isn’t ready. Push too fast or too far, and there’ll be a backlash.

For newer members of the party’s caucus, the older generation’s fear of a backlash is befuddling. “Leadership is driven by fear. They seem to be unable to lead,” said Corbin Trent, a spokesman for Ocasio-Cortez and a co-founder of Justice Democrats, the insurgent political organization that powered her rise, while also backing Omar and Tlaib. “I’m not sure what caused it.”

The answer, in short: the Gipper.

The way the older and younger House members think about and engage with the Republican Party may be the starkest divide between them. Democratic leaders like Pelosi, Joe Biden, Steny Hoyer and Chuck Schumer were shaped by their traumatic political coming-of-age during the breakup of the New Deal coalition and the rise of Ronald Reagan — and the backlash that swept Democrats so thoroughly from power nearly 40 years ago. They’ve spent the rest of their lives flinching at the sight of voters. When these leaders plead for their party to stay in the middle, they’re crouching into the defensive posture they’ve been used to since November 1980, afraid that if they come across as harebrained liberals, voters will turn them out again.

The Ocasio-Cortezes of the world have witnessed the opposite: The way they see it, Democratic attempts to moderate and compromise have led to nothing but ruin. Republicans aren’t the ones to be afraid of. “The greatest threat to mankind is the cowardice of the Democratic Party,” Trent told me.

House Speaker Nancy Pelosi (D-Calif.) has urged her party to “own the center left, own the mainstream.” (Leah Millis/Reuters)

It’s hard to overstate how traumatizing that 1980 landslide was for Democrats. It came just two years after the rise of the New Right, the Class of ’78 led by firebrands like Newt Gingrich, and it felt like the country was repudiating everything the Democrats stood for. The party that had saved the world from the Nazis, built the modern welfare state, gone to the moon and overseen the longest stretch of economic prosperity in human history was routed by a C-list actor. Reagan won 44 states.

That November saw not just Jimmy Carter defeated but a generation of liberal lions poached from the Senate. A net loss of 12 Democrats flipped the chamber to the Republicans. The Democratic nominee for president in 1972, war hero George McGovern, was ousted. Frank Church, first elected in 1956, had been chairman of the forerunner to the Select Committee on Intelligence. In 1976, he was a credible presidential candidate; in 1980, he was out of a job. Same with Birch Bayh, another presidential hopeful who’d served nearly 20 years in the Senate. Warren Magnuson, first elected in 1944, was chairman of the Appropriations Committee and the senior-most member of the Senate. Even Mike Gravel, a hero of the Pentagon Papers battle and a voice of the antiwar left, was beaten that year in a primary, leading to a fall GOP pickup of his seat. Collectively, the defeated Democrats represented every plank of liberalism — whether it was support for workers or the environment or opposition to militarism or racism. They were the party.

Politicians like Pelosi, Schumer and Hoyer were just coming into their own. The lesson they took was that the party had gotten too liberal in the late ’60s and ’70s, and the Reagan Revolution was payback. They became convinced that the United States was a center-right country and that they had to accede to that unfortunate reality. For that reason, the wing of the party that had backed Ted Kennedy in the primaries against Carter in 1980 could be safely ignored. Reagan won a landslide reelection four years later. Maybe the country just wasn’t into Democrats. In 1988, Massachusetts Gov. Michael Dukakis let a nearly 20-point lead in the polls slip away as he lost to Reagan’s hapless vice president, the tongue-tied patrician George H.W. Bush, despite the Iran-contra scandal and eight years of GOP control. That only further persuaded the Democratic elite that liberalism was on the outs.

They kept finding proof: When Bill Clinton beat Bush and Ross Perot by pulling in 43 percent of the vote in 1992, it represented a triumph of the centrist Democratic Leadership Council. When Hillarycare went down in flames and took the House majority with it in 1994, liberalism was again at fault. “I regret very much the efforts on health-care reform were badly misunderstood,” Hillary Clinton said after the ’94 bloodbath, “ . . . and then used politically against Democrats. So I take responsibility for that, and I am very sorry about that.”

The following decades would be marked by a defensive posture. Democrats fought to save Head Start but opted to “end welfare as we know it.” For fear of looking weak, they voted for a war in Iraq that many Democratic voters opposed. When Democrats, under the leadership of Pelosi and Rahm Emanuel, reclaimed the House in 2006, they did so on the back of an antiwar wave — but while Emanuel assiduously recruited veterans, he insisted that Democratic candidates not oppose the war. His instructions, instead, were to call merely for a “new direction” and for Defense Secretary Donald Rumsfeld to be fired. When hawkish Democrat Jack Murtha had called for withdrawal from Iraq in late 2005, Emanuel was appalled, thinking Murtha had cost Democrats the next election. “I was wrong, no doubt about it,” he said later, claiming to have warmed to an antiwar message in the waning days of the campaign. Pelosi stopped an effort to end the war by blocking funds for it. “We will not cut funding for the troops,” she declared. Relax, she seemed to be saying. We’re not who you think we are.

Again and again, Democrats since Reagan have gone out of their way to convince the country that they’re not tax-and-spend liberals. When the Clintons and President Barack Obama pushed for universal health care, they framed the fight not just in moral terms, but also with technocratic claims that expanding coverage and reforming the system would reduce long-term budget deficits.

Democrats have been unable to embrace the new political environment in which the progressive agenda is genuinely popular. Support for Medicare-for-all has been rising, but Ways and Means Committee Chairman Richard E. Neal (Mass.), first elected to the House in 1988, warned Democrats not to mention the phrase during a hearing intended to be about legislation to establish it. Roe v. Wade, meanwhile, has the support of roughly 4 in 5 Americans, while 65 percent of voters in battleground congressional districts back a $15-an-hour minimum wage. But Reagan haunts leaders, even in their vocabulary, which is still infected with the term “Reagan Democrat” — as if a voter who abandoned the party nearly 40 years ago is anything other than a Republican. “Those ethnic, blue collar voters, what we refer to as ‘Reagan Democrats,’ they are the people we need to turn the Electoral College on Trump,” Larry Rasky, a long-time consultant to Biden, told Politico in April, promising that Biden was the man who would end their decades-long flirtation with the GOP and bring them “back into the Democratic fold.”

“For new members, what’s important isn’t just winning but fighting,” said Rep. Alexandria Ocasio-Cortez (D-N.Y.). (Salwan Georges/The Washington Post)

For people under a certain age, this slinking in the corner is deeply strange behavior. Young people in the 1990s watched Bill Clinton work with Republicans — to overhaul welfare, try to cut Social Security, deregulate Wall Street — only to see them turn around and impeach him. In the 2000s, they watched Democrats halfheartedly support a war they opposed. Then Obama tried to compromise with Republicans on the size of a post-crash stimulus and the nature of the Affordable Care Act.

None of it calmed Republicans, as younger lawmakers see it, so why not try something else? “The older members really cling to the idea that things are going to go ‘back to normal’ ” after Trump, Ocasio-Cortez told me. “For us, it’s never been normal, and before that the bipartisanship was s—ty anyway and gave us the War on Drugs, DOMA” — the Defense of Marriage Act, which barred federal recognition or benefits for same-sex couples — “and stripping the leg[islative] branch of everything.”

Still, Pelosi’s fear is that the energetic left will define the party in the eyes of a mythical center. “Own the center left, own the mainstream,” Pelosi has urged her caucus, advising Democrats to “not engage in some of the other exuberances that exist in our party.”

Otherwise, she warned, Democrats will win the White House by only a small margin next year, and Trump will contest the results. This fear is genuine but also necessary. In the absence of an affirmative agenda the party can agree on, the Democratic establishment needs something to inspire voters to show up, and fear of Republicans — and Trump — fits the bill.

For the newcomers, this is completely foreign. To them, Republicans shouldn’t be feared, they should be beaten. Ocasio-Cortez told me that she treats Republicans like buffoons because that’s how they’ve behaved for as long as she can remember. “Even before I was of voting age, I saw Republicans accuse the Obamas of doing a ‘terrorist fist bump,’ so they’ve been clowns since I was a teen,” she said.

That fearless approach to electoral politics is seen in only two major presidential candidates: Sens. Elizabeth Warren (Mass.) and Bernie Sanders (I-Vt.). Each was immune to the pox that fell upon the party in the ’80s. Warren told me she voted for Jimmy Carter in 1980 and was no fan of Reagan, but she was barely following politics and was probably a registered Republican then. By the time she got involved in national politics in the 2000s, she was battling corporate-friendly Democrats, as much as Republicans, over bankruptcy policy.

Sanders, too, had no deep investment in the fortunes of the Democratic establishment in the 1980s, as mayor of Burlington, Vt. Sanders endorsed Jesse Jackson’s insurgent 1988 presidential bid and played a critical role in it. He launched his national career from there, elected to Congress as an independent, not a Democrat, in 1990. No wonder Warren and Sanders are now unafraid to express a full-throated progressivism without worrying about an electoral handicap.

Ocasio-Cortez, meanwhile, was born in 1989, by which time Reagan was out of the White House. Her formative political experience was Obama’s first campaign. He was not at all the safe choice in 2008 and won in part because of young voters unafraid to take a chance — becoming the first Democrat to win more than 50 percent of the vote since the 1970s. Ocasio-Cortez phone-banked for Obama as a college student and told me that because her absentee ballot couldn’t arrive in time, she took a Chinatown bus from Boston to New York to cast her vote. Her generation was rewarded for their gamble with his election, and they were hopeful they could trust his informal campaign slogan: “I got this.”

“A lot of us were politicized under Obama,” Varshini Prakash, a co-founder of the Sunrise Movement, which focuses on climate change, told me. “We were like, ‘We don’t need to take control of the government, because . . . there’s this benevolent figure in the government who likes us and cares about the issues we care about, or at least says he does, and all we need to do is convince him of the right course of action.’ And that proved to be untrue.” Whether it was expanding the use of drones to kill militants overseas, ramping up deportations of immigrants here, coming up short on health-care reform, failing to jail a single Wall Street executive for the lending and trading practices that blew up the global financial system or declining to investigate Bush administration officials for presiding over torture, young progressives realized they’d have to fight their own party as well. Prakash said she was particularly stunned to learn that the Obama administration, relying on polling data, advised its green allies to discard the term “climate change” in their messaging. “Clean energy,” officials suggested, would suffice — a rubric that “clean” coal companies and natural gas producers were happy to adopt.

Ocasio-Cortez said she has seen how fear shapes senior members of her caucus and their approach to politics. “When it comes to defending why we don’t . . . push visionary legislation, I hear the line so frequently from senior members, ‘I want to win,’ ” she said. “But what they mean by that is, ‘I only want to introduce bills that have a 100 percent chance of passing almost unanimously.’ But for new members, what’s important isn’t just winning but fighting. I don’t care about losing in the short term, because we know we’re fighting for the long term.”

On the Friday after the midterm elections, an activist with the Sunrise Movement reached out to Ocasio-Cortez’s camp with a request. They planned to occupy Pelosi’s office the following Tuesday, demanding a commitment to push for a green-jobs guarantee. Would Ocasio-Cortez put out a supportive statement? Or perhaps even a tweet?

No, she told them. I’ll join you. But first, you need to demand more.