Democrats celebrated last week after President Trump was forced to wave the white flag over his administration’s effort to include a question about citizenship on the 2020 US Census. But for all the bipartisan bluster over the issue, the immediate stakes were much lower than either Trump or his critics claimed. The cultural symbolism, however, mattered a great deal.

It is unlikely that many illegal immigrants or others who fear the government will participate in the Census — whether the document asks about citizenship or not. Thus, even if Trump had gotten his way, it wouldn’t have significantly affected Census results or the composition of Congress, which the Census results shape.

Yet the cultural question at the heart of the debate, having to do with the meaning of citizenship, is worth arguing about. To wit, by going after Trump’s proposal, his opponents ultimately targeted American sovereignty itself.

Democrats claimed that merely asking about citizenship would have discouraged both legal and illegal immigrants, and even some citizens, from answering the Census. They accused Trump of trying to cook the numbers to undercount the population in immigrant-heavy blue districts and boost Republicans’ chances of controlling Congress.

Nonsense. The Census already probes respondents about their race and whether they are Hispanic. Citizenship status is at least as pertinent. The US Census used to probe citizenship on the short form as recently as the 1950s. As these pages have noted, moreover, other Western countries, including our Canadian neighbors, still ask about citizenship. Immigration and Customs Enforcement, meanwhile, by law can’t use Census data, so immigrants had nothing to fear from responding.

So why did the American left go into Defcon 1 over Trump’s attempts to ask about citizenship in the Census? Part of the answer has to do with liberals’ determination to resist whatever Trump does.

But far more important is that many in the Democratic Party — including almost all of its 2020 presidential candidates — have embraced a view of illegal immigration that is indistinguishable from advocacy for open borders. Not too long ago, the party sought amnesty for illegal immigrants already in the country, especially those brought here as children.

But their position has now shifted to one in favor of decriminalizing illegal immigration altogether — and even giving ­illegal migrants driver’s licenses, plus taxpayer-funded health care and college tuition.

It’s why abolishing ICE, once a position associated with the fringe of the fringe, is now mainstream among leading Democrats. Rep. Alexandria Ocasio-Cortez has gone so far as to float disbanding the Department of Homeland Security.

The same transnationalist, open-borders ideology is behind so-called sanctuary cities as well as liberals’ opposition to ICE raids over the weekend aimed at detaining and prosecuting illegals. ICE seeks a few thousand illegal immigrants who have already been ordered to leave the country by the courts — a tiny fraction of the millions who are liable for deportation under law.

There is nothing outrageous about this, since those involved have already been afforded due process by immigration courts. But liberals are treating this otherwise mundane and belated effort to enforce the law of the land as evidence of the administration’s barbarism and cruelty.

The ultimate point of Democratic efforts to hamstring ICE is to treat laws against illegal immigration as fundamentally immoral. Illegally crossing the US border, liberals think, should be treated the same way as jaywalking on our streets — that is, a civil violation.

Asking Census respondents about their citizenship status would have suggested that these distinctions matter. So would supporting ICE’s efforts to ­locate and deport illegal ­migrants. The aim is to blur the lines between citizens and non-citizens, and ­legal and illegal migrants, to the point where there is no effective difference between these various groups.

In other words, the very concept of citizenship is now a hallmark of Trumpian oppression in the liberal mind.

So, yes, while the argument over the Census was perhaps much ado about nothing, the underlying debate about citizenship is very significant indeed. To the extent that Democrats are chipping away at these distinctions, they are undermining respect for US sovereignty and the rule of law, bedrocks of American democracy.

That’s a dangerous game that no responsible politician should be playing — no matter what he thinks of Trump.

Jonathan Tobin is editor in chief of JNS.org and a contributing writer for National Review.