A look back at Barack Obama’s January 2013 speech unveiling his second-term push for immigration reform provides dramatic evidence of how much the politics of this high-decibel issue have changed in eight years.

In his address at a Las Vegas high school, Obama highlighted what he claimed was the guiding principle of his reform efforts: “First, I believe we need to stay focused on enforcement. That means continuing to strengthen security at our borders.”

As Joe Biden begins his own pitch for immigration reform, this kind of fortify-the-border rhetoric is nowhere to be found.

The closest Biden comes to this traditional political refrain is pushing a plan to “supplement existing border resources with technology and infrastructure.” But as the White House fact sheet indicates, that is mostly about stopping international narcotics trafficking.

My goal here is not to encourage frenzied Trumpian chants of “Build the wall.”

In truth, Donald Trump’s hate-mongering about immigrants and his administration’s chilling child separation policies did discredit aggressive border enforcement. Also, Trump’s wall-them-out fury ignored the reality that millions of immigrants have legally arrived at major airports and then overstayed their tourist visas.

The Biden plan — for all its uncertain congressional future — reflects a significant turnabout in how major legislation is constructed.

Let me offer a visual aid in the form of a famous New Yorker cartoon from the 1920s. It’s the one in which a little girl responds to her mother’s insistence that the green stuff on her plate is broccoli by snapping, “I say it’s spinach, and I say the hell with it.”

We seem to have reached the end of the “hell with spinach” era of legislating.

Immigration was the prime example. Both George W. Bush’s plan and successor efforts under Obama were built around trade-offs that neither side liked: Republicans got enhanced border enforcement and more guest workers, while the Democrats got a path to citizenship for millions in the country without valid papers.

It was what political Washington considered a grand bargain — a plan that could unite the Chamber of Commerce and La Raza.

There was only one problem, as both Bush and Obama discovered to their distress: Conservative and liberal voters didn’t understand the big-ticket immigration compromise. As a result, its provisions were assailed from both the right (amnesty) and the left (it’s mostly border enforcement).

Health care offered another version of this flawed approach. The Affordable Care Act was crafted by Obama and congressional Democrats in a deliberate (and ultimately futile) effort to win Republican votes.

As a result, the 2010 legislation — which was partially modeled on Mitt Romney’s health care program in Massachusetts as governor — was maddingly complex. Yes, GOP demonology played a significant role in the relative unpopularity of Obamacare until a turnabout in the polls occurred after Trump and the congressional Republicans came close to killing it in 2017.

But all the bells and whistles, all the subsidies and incentives, all the emphasis on market forces made the Affordable Care Act hard for anyone — even liberals — to love. That partly explains the popularity of “Medicare for All” during the 2020 Democratic primaries.

While it is too early to make an absolute judgment one month into a new administration, Biden appears to have embraced a new theory of legislating with a closely divided Congress.

Rather than playing for GOP votes with provisions that the Democratic base hates, Biden’s approach is to signal a willingness to make his package smaller if that’s what is required for Congress to pass it.

The $1.9 trillion economic stimulus fits this pattern perfectly.

If the Senate parliamentarian rules that a $15-an-hour minimum wage cannot be included under reconciliation, Biden is prepared to jettison it. Earlier, White House Press Secretary Jen Psaki made clear that the $1.9 trillion figure was not writ in stone, although Biden did demand a package large enough to meet the challenges of the pandemic.

Immigration fits the same pattern. The message radiating from the Biden White House is that the president is realistic enough to begin with the most popular parts of his proposal as stand-alone legislation.

That would presumably mean legalizing and offering a path to citizenship for “Dreamers,” those undocumented immigrants who were brought to this country as children. There might also be a push to provide the same opportunities to the roughly 1 million farm workers here without valid papers.

In prior years, there would have been a far greater political reluctance to single out Dreamers for special legislation since they are, by far, the most sympathetic figures in the immigration debate. Only a hard-hearted Trump true believer would want to deport Dreamers, who often have no memories of the country of their birth.

In a political world dominated by social media and cable TV, the underlying rule of legislating is simple: If you can’t explain to your supporters what you’re doing, then the effort on Capitol Hill is doomed.

No longer can insiders get away with saying in a patronizing tone, “You wouldn’t understand. But this is what we had to do to get the bill through Congress.”

The point is not that the era of comprehensive bipartisan legislation is over, although there are obvious challenges to pulling off anything ambitious in such a narrowly divided Congress.

What is clear is that there is no appetite in either party to accept spinach as part of any legislative deal — even if it is disguised as broccoli.

Walter Shapiro has covered the last 11 presidential campaigns. He is also a fellow at the Brennan Center for Justice at NYU and a lecturer in political science at Yale. Follow him on Twitter @MrWalterShapiro.