When President Trump’s policy adviser Stephen Miller stepped to the podium of the White House briefing room on Wednesday to defend a plan for reducing levels of legal immigration, Jim Acosta of CNN was aghast and let everyone know it.

Put aside that Acosta believed it was his role as a reporter to argue one side of a hot-button political issue (this is how journalism works in 2017). The exchange illustrated how advocates of high levels of immigration are often the ones who — despite their self-image as the rational bulwark against runaway populism — rely on an ignorant emotionalism to make their case.

At issue is the bill sponsored by Republican Sens. Tom Cotton of Arkansas and David Perdue of Georgia to cut legal immigration by half. The legislation would scale back so-called chain migration — immigrants bringing relatives, who bring more relatives in turn — and institute a merit-based system for green cards based on the ability to speak English, educational attainment and job skills.

Offended by the idea of putting a priority on higher-skilled immigrants, Acosta wanted to know how such a policy would be consistent with the Statue of Liberty. When Miller pointed out that Lady Liberty was conceived as a symbol of . . . liberty and the famous Emma Lazarus poem added later, Acosta accused him of “national park revisionism” — even though Miller was correct.

That might seem pedantic, but the underlying debate is over the legitimacy of reducing levels of immigration and whether it is appropriate to craft a policy mindful, above anything else, of the national interest. Miller clearly has the best of this argument.

One, making 21st century policy in accord with late-19th century poetry makes no sense.

Two, the cap on refugees in the Cotton-Perdue bill of 50,000 a year is in the ballpark of recent annual refugee numbers. We actually admitted fewer than this in the late-1970s and early-2000s, and the Statue of Liberty still stood.

Three, although Acosta angrily objected to giving a preference to English speakers, knowing English helps people make their way in this country, and it’s reasonable to want immigrants to speak the language. As Miller pointed out, this is already a requirement for naturalization.

And every comprehensive immigration-reform bill always makes at least a symbolic nod to undocumented immigrants learning English before receiving amnesty.

Fourth, despite the myth, immigration policy has been highly contested throughout American history, and levels have ebbed and flowed. Acosta seems to think that the current status quo is the norm, when the past 40 years have represented a historic wave of immigration. The usual pattern has been that we tap the brakes after such a spike, but advocates of high levels of immigration consider that un-American.

Cotton-Perdue can’t be considered ungenerous in light of how latitudinarian we have been for so long.

We have the largest immigrant population in the world, and are home to 20 percent of all the world’s immigrants. Immigrants and their children and grandchildren — 72 million people altogether — have accounted for a majority of US population growth since 1965.

The share of the population that is foreign-born will soon eclipse the record of 15 percent from around the turn of the 20th century.

The Cotton-Perdue merit system for green cards is hardly know-nothingism. It could, in fact, be described with that cliched banal phrase — “a worthwhile Canadian initiative.” The bill cribs from the points systems in both Canada and Australia, neither of which are considered benighted countries.

And an emphasis on skills will take some of the pressure of immigration off of the country’s low-skilled workers. Employers may complain about losing access to immigrant labor, but it is simply not true that there are jobs that Americans won’t do. Almost every occupational category in the country has a majority of native-born workers. If there is really such a dearth of low-skilled labor in this county, wages should be rising smartly for these workers, and they aren’t.

If nothing else, Cotton-Perdue will force a debate in an area in which thoughtless sentimentality has long dominated — and if the Miller-Acosta exchange is any indication, will be difficult to dislodge.