Last week, the Trump administration doubled down in its fight against birthright citizenship. The usual alliance of pundits, professors and press lined up to declare any challenge to birthright citizenship as absurd. Yet the administration seemed not only undeterred, but delighted.

There is a reason for that euphoria: They believe that they cannot lose this fight.

The legal case against birthright citizenship has always been tough to make, given the long-standing interpretation of the Fourteenth Amendment in federal courts and agencies. Many in academia and the media have shown unusual outrage toward anyone questioning the basis for birthright citizenship as a legal or policy matter.

On birthright citizenship, roughly half of the country now opposes it, according to a recent Emerson poll.

That is consistent with much of the world.

The U.S. is actually in the minority on the issue.

Our closest allies in Europe reject birthright citizens and follow the common practice of “jus sanguinis,” or right of blood.

We are part of a smaller number of countries following “jus soli,” or right of soil.

That is why the Trump administration may win either way. It will either secure a new interpretation from the high court or it could spur a campaign for a constitutional amendment. All of this could unfold around the time of the midterm elections, when incumbents of the president’s party are generally disfavored. This is a wedge issue that many in the Republican Party might welcome.

Indeed, the most relevant quote from the Civil War period may be that of Gen. Ulysses S. Grant in the final year of the war, when he declared “I propose to fight it out on this line if it takes all summer.” It was a war of attrition, and Grant liked the odds. Some conservatives seem to have the same view of the lay of the land in the fight over birthright citizenship.